I'm trying to share an Excel workbook, but with limited access to only a couple of visible sheets. This have proven to be much harder than first anticipated due to security loopholes with Excel and password protection of worksheets.
My problem arises due to some hidden sheets that needs to stay hidden and the contents inaccessible, but are required for calculations were the result is shown in the visible sheets.
So far I have tried to "super hide" the sheets in the VBA window and lock the VBA project. The idea is that the user then can't unhide the "super hidden" sheets without the VBA project password.
I have tried to add additional VBA code to counter certain "attacks", but I keep coming back to a known flaw that circumvents all my efforts:
Step 1:
Save or make sure that the Excel workbook is saved as .xlsx or .xlsm
Step 2:
Run the following code from a different workbook or your personal.xlsb that removes passwords from sheets and structure protection
(I would have linked to the post where I found the code, but I can't find it right now...).
Sub RemoveProtection()
Dim dialogBox As FileDialog
Dim sourceFullName As String
Dim sourceFilePath As String
Dim SourceFileName As String
Dim sourceFileType As String
Dim newFileName As Variant
Dim tempFileName As String
Dim zipFilePath As Variant
Dim oApp As Object
Dim FSO As Object
Dim xmlSheetFile As String
Dim xmlFile As Integer
Dim xmlFileContent As String
Dim xmlStartProtectionCode As Double
Dim xmlEndProtectionCode As Double
Dim xmlProtectionString As String
'Open dialog box to select a file
Set dialogBox = Application.FileDialog(msoFileDialogFilePicker)
dialogBox.AllowMultiSelect = False
dialogBox.Title = "Select file to remove protection from"
If dialogBox.show = -1 Then
sourceFullName = dialogBox.SelectedItems(1)
Else
Exit Sub
End If
'Get folder path, file type and file name from the sourceFullName
sourceFilePath = Left(sourceFullName, InStrRev(sourceFullName, "\"))
sourceFileType = Mid(sourceFullName, InStrRev(sourceFullName, ".") + 1)
SourceFileName = Mid(sourceFullName, Len(sourceFilePath) + 1)
SourceFileName = Left(SourceFileName, InStrRev(SourceFileName, ".") - 1)
'Use the date and time to create a unique file name
tempFileName = "Temp" & Format(Now, " dd-mmm-yy h-mm-ss")
'Copy and rename original file to a zip file with a unique name
newFileName = sourceFilePath & tempFileName & ".zip"
On Error Resume Next
FileCopy sourceFullName, newFileName
If Err.Number <> 0 Then
MsgBox "Unable to copy " & sourceFullName & vbNewLine _
& "Check the file is closed and try again"
Exit Sub
End If
On Error GoTo 0
'Create folder to unzip to
zipFilePath = sourceFilePath & tempFileName & "\"
MkDir zipFilePath
'Extract the files into the newly created folder
Set oApp = CreateObject("Shell.Application")
oApp.Namespace(zipFilePath).CopyHere oApp.Namespace(newFileName).Items
'loop through each file in the \xl\worksheets folder of the unzipped file
xmlSheetFile = Dir(zipFilePath & "\xl\worksheets\*.xml*")
Do While xmlSheetFile <> ""
'Read text of the file to a variable
xmlFile = FreeFile
Open zipFilePath & "xl\worksheets\" & xmlSheetFile For Input As xmlFile
xmlFileContent = Input(LOF(xmlFile), xmlFile)
Close xmlFile
'Manipulate the text in the file
xmlStartProtectionCode = 0
xmlStartProtectionCode = InStr(1, xmlFileContent, "<sheetProtection")
If xmlStartProtectionCode > 0 Then
xmlEndProtectionCode = InStr(xmlStartProtectionCode, _
xmlFileContent, "/>") + 2 '"/>" is 2 characters long
xmlProtectionString = Mid(xmlFileContent, xmlStartProtectionCode, _
xmlEndProtectionCode - xmlStartProtectionCode)
xmlFileContent = Replace(xmlFileContent, xmlProtectionString, "")
End If
'Output the text of the variable to the file
xmlFile = FreeFile
Open zipFilePath & "xl\worksheets\" & xmlSheetFile For Output As xmlFile
Print #xmlFile, xmlFileContent
Close xmlFile
'Loop to next xmlFile in directory
xmlSheetFile = Dir
Loop
'Read text of the xl\workbook.xml file to a variable
xmlFile = FreeFile
Open zipFilePath & "xl\workbook.xml" For Input As xmlFile
xmlFileContent = Input(LOF(xmlFile), xmlFile)
Close xmlFile
'Manipulate the text in the file to remove the workbook protection
xmlStartProtectionCode = 0
xmlStartProtectionCode = InStr(1, xmlFileContent, "<workbookProtection")
If xmlStartProtectionCode > 0 Then
xmlEndProtectionCode = InStr(xmlStartProtectionCode, _
xmlFileContent, "/>") + 2 ''"/>" is 2 characters long
xmlProtectionString = Mid(xmlFileContent, xmlStartProtectionCode, _
xmlEndProtectionCode - xmlStartProtectionCode)
xmlFileContent = Replace(xmlFileContent, xmlProtectionString, "")
End If
'Manipulate the text in the file to remove the modify password
xmlStartProtectionCode = 0
xmlStartProtectionCode = InStr(1, xmlFileContent, "<fileSharing")
If xmlStartProtectionCode > 0 Then
xmlEndProtectionCode = InStr(xmlStartProtectionCode, xmlFileContent, _
"/>") + 2 ''"/>" is 2 characters long
xmlProtectionString = Mid(xmlFileContent, xmlStartProtectionCode, _
xmlEndProtectionCode - xmlStartProtectionCode)
xmlFileContent = Replace(xmlFileContent, xmlProtectionString, "")
End If
'Output the text of the variable to the file
xmlFile = FreeFile
Open zipFilePath & "xl\workbook.xml" & xmlSheetFile For Output As xmlFile
Print #xmlFile, xmlFileContent
Close xmlFile
'Create empty Zip File
Open sourceFilePath & tempFileName & ".zip" For Output As #1
Print #1, Chr$(80) & Chr$(75) & Chr$(5) & Chr$(6) & String(18, 0)
Close #1
'Move files into the zip file
oApp.Namespace(sourceFilePath & tempFileName & ".zip").CopyHere _
oApp.Namespace(zipFilePath).Items
'Keep script waiting until Compressing is done
On Error Resume Next
Do Until oApp.Namespace(sourceFilePath & tempFileName & ".zip").Items.count = _
oApp.Namespace(zipFilePath).Items.count
Application.Wait (Now + TimeValue("0:00:01"))
Loop
On Error GoTo 0
'Delete the files & folders created during the sub
Set FSO = CreateObject("scripting.filesystemobject")
FSO.deletefolder sourceFilePath & tempFileName
'Rename the final file back to an xlsx file
Name sourceFilePath & tempFileName & ".zip" As sourceFilePath & SourceFileName _
& "_" & Format(Now, "dd-mmm-yy h-mm-ss") & "." & sourceFileType
'Show message box
MsgBox "The workbook and worksheet protection passwords have been removed.", _
vbInformation + vbOKOnly, Title:="Password protection"
End Sub
Step 3:
Run the following code to unhide all sheets
Sub UnhideAllSheets()
For Each Worksheet In ActiveWorkbook.Sheets
Worksheet.Visible = -1
Next Worksheet
End Sub
The workbook is now clean of passwords on sheets and structure protection, and any "counter" VBA code is gone by saving the workbook as a .xlsx file.
I have thought about adding a user-defined function that checks if the extension of the workbook file is ".xlsb". The function would return "1" if the extension is ".xlsb" and then multiplying it on something important. This would cause the calculations to fail if the workbook is saved as something else, or if the VBA project is entirely removed to saving as .xlsx.
However, I do not like this approach as I don't think it is a long-term solution...
My question is therefore:
Is there a way to securely share an Excel workbook with only access to a couple of sheets without risking the user can access hidden sheets and/or unwanted contents?
In the VBE you can change the Visible property of a specific sheet to xlSheetVeryHidden.
This will remove it from the front end completely.
You can then add a password to protect the VBA project in the VBE to prevent a user from changing that property (if they even know about it).
Additionally, you will still be able to access these sheets with your VBA code.
EDIT:
What I also add to the above is a password to the specific sheet, as normal. But also a custom UserForm the UserForm gets triggered on the Worksheet_Activate event if they had to unhide it. If they enter the incorrect password or close the UserForm the sheet gets hidden away again. You can add all sorts to this event handler such as reprotect the worksheet, reprotect the project, protect the workbook with an encrypted password and close the workbook as a "breach" in security.
The possibilities are endless. Not an exact prevention, but hopefully this helps.
Related
I'm trying to write a simple macro to run on my Mac (Excel 16.61, Mac Book Pro running Big Sur 11.4) that copies the visible rows of a table into a new workbook then saves the new workbook as a *.csv file.
The current (non-working) code:
Sub Macro()
Dim wb as Workbook
Dim wbOutput As Workbook
Dim FilePath As String
Set wb = ThisWorkbook
FilePath = "/path/to/filename.csv"
' Copy the visible rows of a filtered table
With wb.Sheets("WorksheetName").ListObjects("tblName")
.Range.AutoFilter Field:=18, Criteria1:="TRUE"
.Range.SpecialCells(xlCellTypeVisible).Copy
End With
' Paste the copied table rows into a new workbook and save as a *.csv file
Set wbOutput = Workbooks.Add
wbOutput.Worksheets("Sheet1").Range("A1").PasteSpecial xlPasteValues
wbOutput.SaveAs FileName:=FilePath, FileFormat:=xlCSV, CreateBackup:=False
wbOutput.Close
End Sub
When I run it however I get the following error:
Run-time error '1004': Cannot access read-only document [filename]
Having spent a few hours searching on-line, I'm no closer to a solution. The internet's suggestions include:
Adding Excel in System Preferences.../Security & Privacy/Files and Folders (I can't see an obvious way of adding a new app, just remove the access rights of apps that already have folder access)
The GrantAccessToMultipleFiles function, but adding FilePath in the input array of the function makes no difference.
How can I create a *.csv file from the table?
Ran into the same issue but my file format was .txt but here was my solution after doing some research and getting some solid help from the Mac VBA Guru Ron De Bruin.
The code essentially bypass creating the output files, in my case .txt files in a folder location that has security protocols that cause the Error 1004 message and creates a subfolder in the Microsoft Folder under my User profile which for whatever reason Excel/Mac don't see as a security threat and allows the VBA to create/save the output file(s) into that folder.
Hopefully, you can extract out what you need from the code and Function to get yours to work. One other thing, since the output is going to such a weird folder location I suggest you save the folder path under your favorites on the Finder Left Panel so you can easily get to the files. See the MsgPopup box for the folder location
Sub Create_TxtFiles()
Dim MacroFolder As String
Dim nW As Workbook
Dim ws1 As Worksheet, ws2 As Worksheet
Dim DT As String, RelativePath As String, wbNam1 As String, wbNam2 As String, Filepath As String
'Declarations
Set ws1 = ThisWorkbook.Sheets("Extract1")
Set ws2 = ThisWorkbook.Sheets("Extract2")
RelativePath = ThisWorkbook.Path & "/"
DT = Format(CStr(Now), "mm_dd_yyyy hh.mmam/pm")
wbNam1 = "Extract 1 Output" 'Creates the File Name
wbNam2 = "Extract 2 Output" 'Creates the File Name
MacroFolder = "Upload Files"
Call CreateFolderinMacOffice2016(MacroFolder)
'set the savepath as the obscure folder vba has access to'
savepath = Application.DefaultFilePath & MacroFolder & "/"
'copy the Output 1
ws1.Copy
ActiveWorkbook.SaveAs savepath & wbNam1 & DT & ".txt", FileFormat:=42
Workbooks(wbNam1 & DT & ".txt").Close
'copy the Output 2
ws2.Copy
ActiveWorkbook.SaveAs savepath & wbNam2 & DT & ".txt", FileFormat:=42
Workbooks(wbNam2 & DT & ".txt").Close
Application.ScreenUpdating = True
msgbox ("Upload file saved to folder: " & vbNewLine & vbNewLine & savepath)
End Sub
Function CreateFolderinMacOffice2016(NameFolder As String) As String
'Function to create folder if it not exists in the Microsoft Office Folder
'Ron de Bruin : 1-Feb-2019
Dim OfficeFolder As String
Dim PathToFolder As String
Dim TestStr As String
OfficeFolder = Application.DefaultFilePath
PathToFolder = OfficeFolder & NameFolder
On Error Resume Next
TestStr = Dir(PathToFolder & "*", vbDirectory)
On Error GoTo 0
If TestStr = vbNullString Then
MkDir PathToFolder
End If
CreateFolderinMacOffice2016 = PathToFolder
End Function
I'm writing a code to delete a log entry in a .csv file. The code starts with opening the .csv file, using Application.Match to return the row number, and then deleting that and closing the file again. The problems I'm experiencing are I get a type mismatch (my error handling is activated) OR (and here it gets weird) it works (a match is found, the row is deleted) but then the logfile is messed up - all data is one string in column a with either ";" or "," delimiters (this varies somehow, relevant note: I use Dutch language excel). Of course, this makes it impossible for the macro to find a match in any case.
I found that the type mismatch problems I'm experiencing will most likely be caused by the code not finding a match, and this is what I don't understand since I checked and doublechecked the input and the data in the logfile - by all means it simply should find a match. And sometimes it does find a match, deletes the row and messes up formatting. (NOTE: Mostly it does NOT find a match.)
I check data in the .csv file before running the macro. I have tried running the macro with the .csv file already opened. I have tried to Set the matchArray from outside the With. I have tried both sweet talking my laptop and a more aggressive approach, to no avail.
Sub DeleteRowFromFile(ByVal matchValue As String)
Dim filePath As String
Dim fileName As String
Dim fileType As String
Dim matchArray As Range
Dim rowToDelete As Variant
'Naming variables for flexibility
filePath = "C:\Users\Maxim\Documents\Log\"
fileName = "TestRegister"
fileType = ".csv"
Application.ScreenUpdating = False
Workbooks.Open (filePath & fileName & fileType)
With Workbooks(fileName).Worksheets(1)
Set matchArray = .Range("A:A") 'set range in the logfile
'Type mismatch here:
rowToDelete = Application.Match(matchValue, matchArray, 0)
If Not IsError(rowToDelete) Then
Rows(rowToDelete).Delete
Else:
MsgBox "Orderno. " & matchValue & " not found.", vbOKOnly + vbExclamation, "Error"
End If
End With
'Closing the log file
Workbooks(fileName).Close SaveChanges:=True
Application.ScreenUpdating = True
End Sub
Sub MatchAndDelete()
Dim matchValueRange As String
matchValueRange = ActiveWorkbook.Worksheets(1).Range("A1").Value
DeleteRowFromFile (matchValueRange)
End Sub
Footnote:
I'm a struggling enthusiast, I have a lot to learn. Sorry in advance if I have left out any crucial information for you to be of help, and thanks a lot for any and all help.
When you open or save a csv file using a VBA macro Excel will always use the standard (US English delimiters) while if you do the same via the user interface it will use the separators as defined in the Windows regional settings, which probably is ";" in your case.
You can check with .?application.International(xlListSeparator) in the immediate window of your VBEditor.
You can tell Excel to use a different separator, by e.g. adding sep=; as line 1 of your file. Hoever this entry is gone after opening the file. The following code - added before you open the csv file will add this:
Dim oFSo As Object
Dim oTxtFile As Object
Dim strData As String
Set oFSo = CreateObject("Scripting.FileSystemObject")
strData = oFSo.OpenTextFile(filePath & fileName & fileType, 1).ReadAll
Set oTxtFile = oFSo.OpenTextFile(filePath & fileName & fileType, 2)
oTxtFile.writeline "sep=;"
oTxtFile.writeline strData
oTxtFile.Close
You can save your changed file by using the Excel UserInterface Shortcuts via the Application.SendKeys thus achieving what you want:
Application.SendKeys ("^s") 'Save
Application.SendKeys ("^{F4}") 'Close
Dont run this code from the VBE Immeditate window as it will probabaly act on the wrong file!
The full code - just with an alternate way to make the requested change:
Sub DeleteRowFromFile(ByVal matchValue As String)
Dim filePath As String
Dim fileName As String
Dim fileType As String
Dim matchArray As Range
Dim rowToDelete As Variant
Dim oFSo As Object
Dim oTxtFile As Object
Dim strData As String
Dim content As Variant
Dim i As Long
'Naming variables for flexibility
filePath = "C:\Users\Maxim\Documents\Log\"
fileName = "TestRegister"
fileType = ".csv"
Application.ScreenUpdating = False
'Adding "sep =" ; as line 1 of the log file
Set oFSo = CreateObject("Scripting.FileSystemObject")
strData = oFSo.OpenTextFile(filePath & fileName & fileType, 1).ReadAll
Set oTxtFile = oFSo.OpenTextFile(filePath & fileName & fileType, 2)
oTxtFile.writeline "sep=;"
oTxtFile.writeline strData
oTxtFile.Close
'Open logfile
Workbooks.Open (filePath & fileName & fileType)
'Make your changes
With Workbooks(fileName).Worksheets(1)
content = .UsedRange.Value
For i = UBound(content, 1) To 1 Step -1
If content(i, 1) = matchValue Then
.Rows(i).Delete
End If
Next i
End With
'Closing the log file via Sendkeys using excel shortcuts
Application.SendKeys ("^s") 'Save
Application.SendKeys ("^{F4}") 'Close
Application.ScreenUpdating = True
I think that Match it is not required. Try this one.
Sub DeleteRowFromFile(ByVal matchValue As String)
Dim filePath As String
Dim fileName As String
Dim fileType As String
Dim matchArray As Range
Dim rowToDelete As Variant
'Naming variables for flexibility
filePath = "C:\Users\Maxim\Documents\Log\"
fileName = "TestRegister"
fileType = ".csv"
Application.ScreenUpdating = False
Workbooks.Open (filePath & fileName & fileType)
With Workbooks(fileName).Worksheets(1)
For i = .UsedRange.SpecialCells(xlCellTypeLastCell).Row To 1 Step -1
If .Cells(i, 1).Value2 = matchValue Then
.Cells(i, 1).EntireRow.Delete
End If
Next
End With
'Closing the log file
Workbooks(fileName & fileType).SaveAs Filename:= _
(filePath & fileName & fileType) _
, FileFormat:=xlCSVMSDOS, CreateBackup:=False 'Saving the file
Workbooks(fileName & fileType).Close 'Closing the file
Application.ScreenUpdating = True
End Sub
Hope it helps
Suppose, we have one folder with only one macro file and every day we are saving excel file in the same folder received via mail. However, filename every day will get changed. I mean to say what ever file we are getting through mail do not have a standard name. Now, we have two files in the same folder.
Can we open another file which we have saved with some random name available in the same folder using a macro? Here, the name of another file is not standard. Additionally, after running a macro, we also want to delete that file.
You can get the filename of the newest file within a directory by this:
Option Explicit
Private Sub GetNewestFilename()
Dim searchDirectory As String
Dim searchPattern As String
Dim currentFilename As String
Dim NewestFilename As String
Dim NewestFiledate As Date
searchDirectory = Application.DefaultFilePath & "\"
searchPattern = "*.xl*"
currentFilename = Dir(searchDirectory & searchPattern, 0)
If currentFilename <> "" Then
NewestFilename = currentFilename
NewestFiledate = FileDateTime(searchDirectory & currentFilename)
Do While currentFilename <> ""
If FileDateTime(searchDirectory & currentFilename) > NewestFiledate Then
NewestFilename = currentFilename
NewestFiledate = FileDateTime(searchDirectory & currentFilename)
End If
currentFilename = Dir
Loop
End If
MsgBox NewestFilename
Dim wb As Workbook
Set wb = Workbooks.Open(searchDirectory & NewestFilename)
' do something
wb.Close SaveChanges:=False
Set wb = Nothing
' Kill searchDirectory & NewestFilename ' Delete the file
End Sub
I am trying to create a macro that will search a folder for a .dat file that contains "OPS"(not case sensitive) in the name, if it finds a file I would like to open it and run another macro, save the file as the original filename.xlsm, and close.
So far, I am able to search for the name but that's about the extent of my knowledge.
Sub Test2()
Dim sh As Worksheet, lr As Long, fPath As String, fName As String, rFile() As Variant
fPath = "C:\Users\ntunstall\Desktop\test\"
ctr = 1
fName = dir(fPath & "*.dat")
Do Until fName = ""
If InStr(fName, "OPS") > 0 Then
ReDim Preserve rFile(1 To ctr)
rFile(ctr) = fName
ctr = ctr + 1
End If
fName = dir
Loop
For i = LBound(rFile) To UBound(rFile)
'The variable rFile(i) represents the workbooks you want to work with.
MsgBox rFile(i)
Next
End Sub
Ideally, this macro would run any time a .dat file containing OPS in the filename is opened. Any help is appreciated, thanks.
To the top add
Dim wb as workbook
and then replace your message box line with
Set wb = Workbooks.Open(fPath & rFile(i))
wb.SaveAs fPath & Split(rFile(i), ".")(0), xlOpenXMLWorkbookMacroEnabled
wb.Close
I tested with a tab deliminated file and it worked well. Your issues may vary if you have a different format.
Not sure why I am getting this error. Please assist in correcting and also, provide a good explanation for the reason. I have 3 subs (from 2 modules) that call each other sequentially. Is the reason for the error message because the file name from the first sub is declared as a variable in the third sub? See code below:
Module1:
Option Explicit
Sub PRM_1_Report_Save()
'
Application.ScreenUpdating = False
Dim PRM_1_New As Workbook ' This is BCRS-PTASKS Unassigned.csv
Set PRM_1_New = Workbooks("BCRS-PTASKS Unassigned.csv")
Dim SaveDir1 As String, prmAfn As String
SaveDir1 = CreateObject("WScript.Shell").SpecialFolders("MyDocuments") & "\PRM Temp Files"
If Len(Dir(SaveDir1, vbDirectory)) = 0 Then MkDir SaveDir1
prmAfn = SaveDir1 & "\PRM_1_TEMP"
Application.SendKeys ("~")
PRM_1_New.SaveAs Filename:=prmAfn, FileFormat:=xlOpenXMLWorkbook
PRM_1_New.Close False
Call PRM_2_Report_Save
Application.ScreenUpdating = True
End Sub
Sub PRM_2_Report_Save()
'
Application.ScreenUpdating = False
Dim PRM_2_New As Workbook ' This is Problem WGM & WGL xref with description.xls
Set PRM_2_New = Workbooks("Problem WGM & WGL xref with description.xls")
Dim SaveDir2 As String, prmBfn As String
SaveDir2 = CreateObject("WScript.Shell").SpecialFolders("MyDocuments") & "\PRM Temp Files"
If Len(Dir(SaveDir2, vbDirectory)) = 0 Then MkDir SaveDir2
prmBfn = SaveDir2 & "\PRM_2_TEMP"
Application.SendKeys ("~")
PRM_2_New.SaveAs Filename:=prmBfn, FileFormat:=xlOpenXMLWorkbook
PRM_2_New.Close False
Application.ScreenUpdating = True
Call Open_PRM_Files
End Sub
Module 2:
Option Explicit
Sub Open_PRM_Files()
'
Application.ScreenUpdating = False
Dim PRM_Dir As String
Dim PRM_1_TEMP As Workbook
Set PRM_1_TEMP = Workbooks("PRM_1_TEMP.xlsx") ' This is the line that get's the error
Dim PRM_2_TEMP As Workbook
Set PRM_2_TEMP = Workbooks("PRM_2_TEMP.xlsx")
PRM_Dir = CreateObject("WScript.Shell").SpecialFolders("MyDocuments") & "\PRM Temp Files"
Workbooks.Open Filename:=PRM_Dir & "\" & PRM_1_TEMP
Workbooks.Open Filename:=PRM_Dir & "\" & PRM_2_TEMP
Application.ScreenUpdating = True
End Sub
This line from the sub in Module2 is where the debugger shows the error (which is also commented in the sub above):
Set PRM_1_TEMP = Workbooks("PRM_1_TEMP.xlsx")
The purpose of the code here is to save two imported reports into .xlsx format, close them, and then open the files in the saved format. I need this to occur in separate subs (save and open) for other workflow processes of this VBA Project not listed (or relevant) here.
EDIT: I should also mention that the first two subs execute and provide the intended results which is each file saved in the new directory and with the proper extension.
Set PRM_1_TEMP = Workbooks("PRM_1_TEMP.xlsx")
This line assumes that you already have an open workbook with that name. If Excel does not find an open workbook with that name then you will get a runtime error as you noticed.
I'm assuming that you are trying to open the workbooks here which you created in the first two subs:
Workbooks.Open Filename:=PRM_Dir & "\" & PRM_1_TEMP
Workbooks.Open Filename:=PRM_Dir & "\" & PRM_2_TEMP
"& PRM_1_TEMP" is the name of a Workbook variable, and you're trying to concatenate it as a string name. Change this to a string matching the filename, and then move your declarations of workbooks to below the code that opens the workbooks. This way Excel opens the workbooks BEFORE trying to access them in the Workbooks collection, and you should not receive an error. I haven't tested this modification, but please let me know if it works for you.
Sub Open_PRM_Files()
Application.ScreenUpdating = False
Dim PRM_Dir As String
PRM_Dir = CreateObject("WScript.Shell").SpecialFolders("MyDocuments") & "\PRM Temp Files"
Workbooks.Open Filename:=PRM_Dir & "\" & "PRM_1_TEMP"
Workbooks.Open Filename:=PRM_Dir & "\" & "PRM_2_TEMP"
Dim PRM_1_TEMP As Workbook
Set PRM_1_TEMP = Workbooks("PRM_1_TEMP.xlsx") ' This is the line that get's the error
Dim PRM_2_TEMP As Workbook
Set PRM_2_TEMP = Workbooks("PRM_2_TEMP.xlsx")
Application.ScreenUpdating = True
End Sub