Salut opera_8
Tu pourrais mettre une macro comme ceci dans ThisWorkbook.
Private Sub Workbook_SheetActivate(ByVal Sh As Object)
Application.ScreenUpdating = False
Dim mois(1 To 12) As String, i As Byte
mois(1) = "-jan-": mois(2) = "-feb-": mois(3) = "-mar-": mois(4) = "-apr-"
mois(5) = "-may-": mois(6) = "-jun-": mois(7) = "-jui-": mois(8) = "-aug-"
mois(9) = "-sep-": mois(10) = "-oct-": mois(11) = "-nov-": mois(12) = "-dec-"
Columns("A:A").Select
For i = 1 To 9
Selection.Replace What:="" & mois(i) & "", Replacement:=".0" & i & ".", LookAt:=xlPart, _
SearchOrder:=xlByRows, MatchCase:=False
Next i
For i = 10 To 12
Selection.Replace What:="" & mois(i) & "", Replacement:="." & i & ".", LookAt:=xlPart, _
SearchOrder:=xlByRows, MatchCase:=False
Next i
Range("A1").Select
Application.ScreenUpdating = True
End Sub