VBA - lookup in variable workbook - excel

Question

I have a little bit of a problem within an Excel Macro
I have a file populated with huge amount of data extracted from different software and that has to be updated on a monthly basis.
There is data from A2 to O & Lastrow
in column L there is a code that I use to split the sheet into as many sheets as needed (one per existing codes)
Lets say my sheet has 50 lines, the codes present in L are 0250, 40 times and 1225, 10 times so I'll have 2 new sheets
Then all these sheets are saved as individual files for further treatment - and column N of the newly created file will be changed by human
So excel will create a folder and save these 2 sheets as 2 xlsx files according to the month we're in
In my example, it will save them as:
c:\ACCOUNTS\SEP\0250 SEP 19.xlsx
c:\ACCOUNTS\SEP\1225 SEP 19.xlsx
I'm looking for either in the raw extract entirely or at the time the file is split to add in column O a vlookup that will analyze each of these files from the previous month
So I'd like to have a piece of code that will input a Vlookup in the cells, depending of what's in column L of the sheet name to have
=vlookup(A2,c:\ACCOUNTS\AUG\0250 AUG 19.xlsx!A2:O & lastrow,14,0)
or
=vlookup(A2,c:\ACCOUNTS\AUG\1225 AUG 19.xlsx!A2:O & lastrow,14,0)
Sub SPLIT()
Dim main As Worksheet
Dim lastrow As Long
Dim FileExtStr As String
Dim FileFormatNum As Long
Dim xWs As Worksheet
Dim xWb As Workbook
Dim FolderName As String
Set xWb = Application.ThisWorkbook
mBefore = Format(DateAdd("m", -1, Date), "MMM yy")
mPrevious = Format(DateAdd("m", -1, Date), "MMM yy")
Set main = Sheets("Global")
main.Activate
'ActiveSheet.name = "Global"
'Set main = Sheets("Global")
'Calculation of last line
lastrow = main.Cells(Rows.Count, "l").End(xlUp).Row
'MsgBox lastrow
Set FDWDownload1 = Sheets("Global")
Sheets.Add(before:=Sheets("Global")).name = "List"
Set Ref = Sheets("List")
'Creates the table
FDWDownload1.Range("L" & StartPointRow + 1 & ":L" & lastrow).Copy
Ref.Activate
Ref.Range("B2").PasteSpecial Paste:=xlPasteValuesAndNumberFormats
Range("B:B").RemoveDuplicates Columns:=1
Application.CutCopyMode = False
RefLastRow = Ref.Cells(Rows.Count, "B").End(xlUp).Row
FDWDownload1.Activate
If RefLastRow > 0 Then
'For the second row to the end of the table on the References tab
For i = 3 To RefLastRow
'Copy the header from the download
FDWDownload1.Range("A1:P1").Copy
'Add a new sheet placed after the sheet "Global" & name it according to the reference table
Sheets.Add(after:=Sheets("Global")).name = Ref.Range("B" & i)
Set ws = Application.ActiveSheet
'Paste the header into each newly created sheet
ws.Range("A1").PasteSpecial Paste:=xlPasteValuesAndNumberFormats
ws.Range("A1").PasteSpecial Paste:=xlPasteFormats
'Get the number of the last row on the newly created sheet
ForLastRow = ws.Cells(Rows.Count, "L").End(xlUp).Row
'As the download is grouped in Product Line order find the first and last row of the Product according to the worksheet name
With FDWDownload1
FDWDownload1.Activate
k = .Range("L:L").Find(what:=ws.name, after:=.Range("L1")).Row
l = .Range("L:L").Find(what:=ws.name, after:=.Range("L1"), searchdirection:=xlPrevious).Row
End With
Range("A" & k & ":O" & l).Copy
ws.Activate
ws.Range("A" & ForLastRow + 1).PasteSpecial Paste:=xlPasteValuesAndNumberFormats
Columns("A:P").EntireColumn.AutoFit
Columns("A:O").AutoFilter
Range("A:O").Sort Key1:=Range("C1"), Order1:=xlAscending, Header:=xlYes
ActiveSheet.name = ws.name & " " & "GRIR" & " " & mBefore
Next i
Else
End If
End Sub

Answer 1

Has the solution to be in VBA? If not you should definetly check out PowerQuery which is included in Excel 2016 and higher. Power Query can do exactly what you asked and doesn't need any code.
Anyway, if I understand you correctly you need to set a formula with VBA.
Try this:
Sub set_formula()
lastrow = 10
Path = "C:\Folder\"
workbookname = "Template.xlsx"
sheetname = "Ids"
Range("D13").Formula = "=VLOOKUP(A2,'" & Path & "[" & workbookname & "]" & sheetname & "'!A2:O" & lastrow & ",14,0)"
End Sub