Dim derlig As Long, dercol As Long, DerniereCellule As Range
'--------------------
On Error Resume Next
derlig = Cells.Find(What:="*", After:=Range("A1"), LookIn:=xlFormulas, SearchOrder:=xlByRows, SearchDirection:=xlPrevious).Row
dercol = Cells.Find(What:="*", After:=Range("A1"), LookIn:=xlFormulas, SearchOrder:=xlByColumns, SearchDirection:=xlPrevious).Column
Set DerniereCellule = cells(derlig, dercol)