Sub NouvelleFeuille()
'se lance par les touches de raccourci Ctrl+N
Dim w As Worksheet, n&, vis%
For Each w In Worksheets
If w.Name Like "*###-" & Format(Date, "yy") Then If Val(w.Name) > n Then n = Val(w.Name)
Next
Application.ScreenUpdating = False
With Sheets("Matrice")
vis = .Visible 'mémorise
.Visible = xlSheetVisible 'au cas où la feuille est masquée
.Copy After:=Sheets(Sheets.Count)
.Visible = vis
End With
ActiveSheet.[A2] = Format(n + 1, "000-") & Format(Date, "yy") 'pourquoi utiliser A2 ?
'ActiveSheet.Name = Format(n + 1, "000-") & Format(Date, "yy") 'plus simple non ?
ActiveSheet.Tab.ColorIndex = 44 'orange
End Sub