C'est bon je viens de trouver la solution :
Public Sub copie()
Dim fpath, filename, datee As String
fpath = ActiveWorkbook.path
Sheets("Facture").Copy
datee = Now
datee = Format(datee, "dd-mm-yy hh-mm-ss")
filename = fpath & "\" & datee & "-" & Sheets("Facture").Range("g8").Value & ".xls"
ActiveWorkbook.SaveAs filename
ActiveWorkbook.Close
End Sub
Merci quand même