Sub DataTransfer()
Dim WBNEW As Workbook 'current week's workbook
Dim WBOLD As Workbook 'previous week's workbook
Dim WSNEW As Worksheet 'current week's worksheet
Dim WSOLD As Worksheet 'previous week's worksheet

'Open all relevant workbooks also make them macro enabled?
Set WBNEW = Workbooks("wk8.xlsm") 'change name of current week's workbook
Set WBOLD = Workbooks("wk7.xlsm") 'change name of previous week's workbook
Set WSNEW = WBNEW.Worksheets("Open cases") 'change if relevant worksheet has different name
Set WSOLD = WBOLD.Worksheets("Open cases") 'change if relevant worksheet has different name

Dim last As Double
With WSNEW
        last = .Cells(.Rows.Count, "C").End(xlUp).Row
End With
'counts the last row

Dim inew As Range
Set inew = WSNEW.Range("A2:A" & last)
'sets the range to be searched in previous week's workbook (Col 1 all rows)

Dim i As Variant
Dim v1 As String
Dim v2 As String
Dim v3 As String

For Each i In inew
    v1 = Application.VLookup(i, WSOLD, 38, False)
    v2 = Application.VLookup(i, WSOLD, 39, False)
    v3 = Application.VLookup(i, WSOLD, 40, False)
    Next
    On Error Resume Next
End Sub