Sub CopierColler()
Dim w As Worksheet, dercel As Range, n&
For Each w In Worksheets
w.Rows("5:" & w.Rows.Count).Sort w.[C5], xlAscending, Header:=xlYes 'tri de sécurité
Set dercel = w.Range("C" & w.Rows.Count).End(xlUp)
If dercel.Row > 5 Then
n = Application.CountIf(w.[C:C], dercel) 'nombre de lignes à copier
With w.Rows(dercel.Row + 1).Resize(n) 'plage du coller
w.Rows(dercel.Row - n + 1).Resize(n).Copy .Cells 'copier-coller
On Error Resume Next 'si aucune constante
.SpecialCells(xlCellTypeConstants) = "" 'effacement
.Columns(3) = dercel + 1 'incrémentation de la date
On Error GoTo 0
End With
End If
Next
End Sub