Sub copie()
Dim plage As Range, semdep As String, nbsem As String, intv As String
Dim L As Long, NoSem As Byte
Set plage = Range("C1:H1")
semdep = InputBox("Semaine de départ ?")
If semdep = "" Then Exit Sub
nbsem = InputBox("combien de semaine ?")
If nbsem = "" Then Exit Sub
intv = InputBox("intervalle ?")
If intv = "" Then Exit Sub
For i = 1 To Int(nbsem)
L = Range("B65000").End(xlUp).Row + 1
NoSem = Int(semdep + (intv * i) - intv)
If NoSem > 52 Then Exit For
plage.Copy
Range("C" & L & ":H" & L).PasteSpecial Paste:=xlAll
Range("B" & L) = NoSem
Next
Application.CutCopyMode = False
End Sub