incrémentation automatique dans formulaire

Private Sub btnAjout_Click()
    '---
    Range("A4").Select
    '---
    ActiveCell.Offset(0, 7).Value = Val(TxtBDD) 'convertit en nombre
    '---

Private Sub btnAjout_Click()
   Dim dl As Long, x As Long
   Application.ScreenUpdating = False
   With Sheets("BIR_2019")
      dl = .Range("A" & Rows.Count).End(xlUp).Row
      .Cells(dl + 1, 1) = CboNomClient.Value
      .Cells(dl + 1, 2) = TxtRefClient
      .Cells(dl + 1, 7) = CDbl(TxtOT)
      .Cells(dl + 1, 8) = CDbl(TxtBDD)
      .Cells(dl + 1, 3) = TxtAdresse
      .Cells(dl + 1, 4) = CDbl(CboVilleCodePostal)
      .Cells(dl + 1, 13) = CboConducteursTravaux
      .Cells(dl + 1, 16) = CboEntreprises
      .Cells(dl + 1, 17) = CboNomsPrenomsEntreprises
      .Cells(dl + 1, 14) = CboGeometre
      .Cells(dl + 1, 15) = CboCartographes
      .Cells(dl + 1, 19) = CDate(TxtDateInterventionTerrain)
      .Cells(dl + 1, 18) = CboMaterielsTopo
      .Cells(dl + 1, 20) = TxtPrecision2D
      .Cells(dl + 1, 21).Value = TxtPrecision3D
   End With
   Application.ScreenUpdating = True
End Sub