Incrémentation numéro facture(je sais encore...mais bon)

Sheets("ma feuille").Range("D6").Value = Left(Range("D6"), 1) + Format(CInt(Right(Range("D6"), Len(Range("D6")) - 1)) + 1, "0000")

Option Explicit

Const NF As String = "Feuil1" '********* A ADAPTER LE NOM DE LA FEUILLE CONTENANT LES N° DE FACTURES ET AVOIRS

Public Function NumeroFacture() As String
Dim num As Integer
    num = CInt(RechercheDernier("F")) + 1
    NumeroFacture = "F" & Right("0000" & num, 4)
End Function
Public Function NumeroAvoir() As String
Dim num As Integer
    num = CInt(RechercheDernier("A")) + 1
    NumeroAvoir = "A" & Right("0000" & num, 4)
End Function
Function RechercheDernier(Quoi As String) As String
Dim R As Range
    Set R = Sheets(NF).Columns(1).Cells.Find(Quoi, After:=Sheets(NF).Range("A" & Rows.Count), LookAt:=xlPart, SearchOrder:=xlByRows, SearchDirection:=xlPrevious)
    If Not R Is Nothing Then
        RechercheDernier = Right(R.Value, 4)
    Else
        RechercheDernier = "0001"
    End If
End Function

Sub plusgdvaltexte(FA As Variant)
Dim pg As Long, c As Range, nu As Variant, yr As Integer
pg = 0
yr = Year(Now())
With Sheets("Numéro facture")
    For Each c In .Range("A2:A" & .Cells(.Rows.Count, 1).End(xlUp).Row)
        If Left(c, 1) = FA And CInt(Right(c, 4)) = yr Then
            nu = Mid(c.Value, 2, 4)
            If pg < nu Then pg = nu
        End If
    Next c
End With
Range("D6") = FA & Format(pg + 1, "0000") & "/" & CStr(yr)
End Sub