Option Explicit
Sub test()
Dim cel1 As Range, cel2 As Range
Set cel1 = Cells.Find("DonneeRecherchée1", , xlValues, xlWhole, , , False)
Set cel2 = Cells.Find("DonneeRecherchée2", , xlValues, xlWhole, , , False)
If Not cel1 Is Nothing And Not cel2 Is Nothing Then
Cells(cel1.Row, cel2.Column).Copy Destination:=Workbooks("nomclasseur.xls").Sheets("Tafeuilledest").Range("A1")
Else
Workbooks("nomclasseur.xls").Sheets("nomfeuille").Range("A1").Value = 0
End If
End Sub