Help Excel formule (SI)

Const Col As Byte = 4 'colonne 4<==>"D" 
Const lig_dep As Byte = 5 'ligne départ 

Sub supprimer_chifffre() 
Dim Derlig As Long, cptr As Long, Plage As Range 
Dim T_out, valeur As Variant 
With ActiveSheet 
     Derlig = Cells(.Rows.Count, Col).End(xlUp).Row 
     Set Plage = .Range(.Cells(lig_dep, Col), .Cells(Derlig, Col)) 
     T_out = Application.Transpose(Plage.Value) 
     For cptr = 1 To UBound(T_out) 
          valeur = T_out(cptr) 
          T_out(cptr) = extrait_lettres(T_out(cptr)) 
     Next 
     'Plage.Offset(0, 2) = Application.Transpose(T_out) 'essai 
     Application.ScreenUpdating = False 
     Plage = Application.Transpose(T_out) 
End With 
End Sub 


Function extrait_lettres(ByRef texto As Variant) As String 
Dim reg As Object 
Dim extraction As Object 
    Set reg = CreateObject("vbscript.regexp") 
    reg.Global = True 
    reg.Pattern = "(\b[a-zA-Zçàâäéèêëïîôöùû]{1,})" 
    Set extraction = reg.Execute(texto) 
    For Each digit In extraction 
        extrait_lettres = extrait_lettres & (digit.Value) 
    Next digit 
    Set extraction = Nothing 
    Set reg = Nothing 
End Function