Private Sub Workbook_SheetActivate(ByVal Sh As Object)
If Not Sh.[E1].Formula Like "=CHOOSE(*" Or Sh.[E1] = Sh.Name Then Exit Sub
For Each Sh In Worksheets
If Sh.[E1].Formula Like "=CHOOSE(*" Then Sh.Name = "µ" & Sh.[E1] 'nom provisoire
Next
For Each Sh In Worksheets
If Sh.Name Like "µ*" Then Sh.Name = Mid(Sh.Name, 2) 'nom définitif
Next
End Sub