Sub test()
Dim Ws As Workbook, Wd As Worksheet
Dim plage As Range, cel As Range
Dim plg As Range, c As Range
Dim x&, Rep$
Application.ScreenUpdating = False
On Error Resume Next
Set Wd = ThisWorkbook.Sheets(1)
x = Wd.Range("a" & Rows.Count).End(xlUp).Row
Wd.Range("c2:c" & x).ClearContents
Set plg = Wd.Range("d2:d" & x)
Rep = ThisWorkbook.Path & "\Classeur2.xlsm"
Set Ws = Workbooks.Open(Rep)
Set plage = Ws.Sheets(1).Range("a2:c" & x)
For Each cel In plage
For Each c In plg
If cel.Value = c.Value Then c.Offset(0, -1) = "ok"
Next c
Next cel
ActiveWorkbook.Close True
End Sub