Sub EnregistrerSous()
Dim NomFichier, x As String, w As String, NomDefaut As String
x = ThisWorkbook.Worksheets("feuil1").Range("a1").Value
w = " " & Format(Date, "dd mm yyyy")
NomDefaut = x & w
NomFichier = Application.GetSaveAsFilename(NomDefaut, "Classeur Excel (prenant en charge les macros (*.xlm), *.xlm")
ActiveWorkbook.SaveAs Filename:=NomFichier
End Sub