[ftho]

Bonjour,

Une piste (loin d'être complète)

Private Sub Worksheet_Change(ByVal Target As Range)
Dim Val, x, i
Val = Target.Value
If Right(Val, 2) = ")!" Then
    For i = 1 To Len(Val) - 2
        If Mid(Val, i, 1) = "!" Then
        x = x + Application.WorksheetFunction.Fact(Mid(Val, i - 1, 1))
        End If
    Next
Target.Offset(0, 1) = Application.WorksheetFunction.Fact(x)
End If
End Sub