How to reffer to workbooks-worksheet and range as variables - excel

Question

I get all the time runtime error 9, “subscript out of range” . Dont know how to do this. I get the error by the last line of code below.
Dim Sheetstarybpm As Worksheet
Dim countrowsoldbpm1 As Long
Dim rng2 As Range
With Application.FileDialog(msoFileDialogFilePicker)
'Makes sure the user can select only one file
.AllowMultiSelect = False
.Title = "Select BPM Report for previous month"
.ButtonName = "OK"
'Filter to just the following types of files to narrow down selection options
.Filters.Add "Excel Files", "*.xlsx; *.xlsm; *.xls; *.xlsb", 1
'Show the dialog box
.Show
oldbpm = .SelectedItems.Item(1)
End With
Workbooks.Open oldbpm
Set Sheetstarybpm = ActiveSheet
countrowsoldbpm1 = Range("a10", Range("a10").End(xlDown)).Rows.Count
Set myrange = Range("A10:CW" & countrowsoldbpm1)
Set rng2 = Workbooks(oldbpm).Worksheets(Sheetstarybpm).Range(myrange)

Answer 1

You are using the object methods incorrectly. Once you have stored the Sheetstarybpm you can use this further... So when opening the workbook store this as a workbook object so you can reference it later on, if needed. Additionally, when setting your worksheet object you can now explicitly reference your workbook because you have stored it (much better coding practice). It is also recommended to explicitly define your sheet object references when setting your ranges. Please see amended code below.
Dim Sheetstarybpm As Worksheet
Dim countrowsoldbpm1 As Long
Dim myWB As Workbook
With Application.FileDialog(msoFileDialogFilePicker)
'Makes sure the user can select only one file
.AllowMultiSelect = False
.Title = "Select BPM Report for previous month"
.ButtonName = "OK"
'Filter to just the following types of files to narrow down selection options
.Filters.Add "Excel Files", "*.xlsx; *.xlsm; *.xls; *.xlsb", 1
'Show the dialog box
.Show
oldbpm = .SelectedItems.Item(1)
End With
Set myWB = Workbooks.Open(oldbpm)
Set Sheetstarybpm = myWB.ActiveSheet
countrowsoldbpm1 = Sheetstarybpm.Range("a10", Range("a10").End(xlDown)).Rows.Count
Set myrange = Sheetstarybpm.Range("A10:CW" & countrowsoldbpm1)
Edit: Removed rng2 from the code because it is the same as myrange, as noted by OP in comments.