Sub b_()
Dim t, n&, x$, F As Worksheet
t = Split(ActiveSheet.Name, ".")
x = t(0): n = CLng(t(1))
On Error Resume Next
Set F = Sheets(x & "." & n + 1)
If Err Then
Err.Clear
Sheets.Add(After:=Sheets(ActiveSheet.Index)).Name = x & "." & n + 1
Else
MsgBox " L'onglet " & x & "." & n + 1 & " est déja présent" & vbLf & vbLf & "traitement interrompu", 1048640, "Feuille existante"
End If
End Sub