Bonjour,
Essaie ainsi :
Sub INSERER()
derln = Range("A" & Rows.Count).End(xlUp)(2).Row
Range("A3:U4").Copy Range("A" & derln)
Range("A3:U4").ClearContents
derln = Range("A" & Rows.Count).End(xlUp).Row
Range("A4") = Application.Max(Range("A4:A" & derln)) + 1
End Sub