Bonjour norberlingo, gmb,
Je te propose ce code VBA :
Private Sub Worksheet_Change(ByVal Target As Range)
With Target
If .Count > 1 Then Exit Sub
If Intersect(Target, [C1:F10]) Is Nothing Then Exit Sub
Application.EnableEvents = False
.Value = UCase$(.Value)
Application.EnableEvents = True
End With
End Sub
dhany