Sub Colonnes_Sup()
Dim dercol As Integer
dercol = Cells(4, Columns.Count).End(xlToLeft).Column
If dercol < 4 Then Exit Sub 'sécurité
Application.ScreenUpdating = False
With Columns(dercol - 3).Resize(, 4) 'correspond à L:O (4 dernières colonnes)
.Copy .Cells(1, 5) 'correspond à P1
.Cells(1, 5).Resize(3, 4) = "" 'correspond à P1:S3
.Cells(5, 5).Resize(Rows.Count - 4, 2) = "" 'correspond à P5:Q1048576
End With
End Sub