XL 2010 Formule sur Numérotation de ligne

Sub Numeroter()
With [A1].CurrentRegion
  If Rows.Count = 1 Then Exit Sub
  .Sort .Columns(1), xlAscending, Header:=xlYes 'tri avec en-têtes
  .Cells(2, 2).Resize(.Rows.Count - 1) = "=IF(RC[-1]<>R[-1]C[-1],1,N(R[-1]C)+1)"
  .Columns(2) = .Columns(2).Value 'supprime les formules, facultatif
End With
End Sub

=(A2=A1)*N(B1)+1

Sub Numeroter()
With [A1].CurrentRegion
  If Rows.Count = 1 Then Exit Sub
  .Sort .Columns(1), xlAscending, Header:=xlYes 'tri avec en-têtes
  .Cells(2, 2).Resize(.Rows.Count - 1) = "=(RC[-1]=R[-1]C[-1])*N(R[-1]C)+1"
  .Columns(2) = .Columns(2).Value 'supprime les formules, facultatif
End With
End Sub

Private Sub Worksheet_SelectionChange(ByVal R As Range)
  If R.Address <> [B1].Address Then Exit Sub
  [Tbo].Sort [Tbo].Item(1, 1), , Header:=1
  [Tbo].Item(1, 2).FormulaLocal = "=SI(A2=A1;B1+1;1)"
  [Tbo[B]] = [Tbo[B]].Value
End Sub

Private Sub CommandButton2_Click()
    [Tbo].Sort [Tbo].Item(1, 1), , Header:=1
    [Tbo].Item(1, 2).FormulaR1C1 = "=IF(RC[-1]=R[-1]C[-1],R[-1]C+1,1)"
    [Tbo[B]] = [Tbo[B]].Value
End Sub