Macro modification de formule de calcul

Sub majFormules()
    Dim c As Range, formule As String, param
    For Each c In Selection
        If Left(c.Formula, 1) = "=" And Mid(c.Formula, 2, 2) <> "IF" Then
            formule = Replace(c.Formula, "/", ";")
            formule = Replace(formule, "-", ";")
            formule = Replace(formule, "=", "")
            param = Split(formule, ";")
            If UBound(param) = 1 Then
                c.Formula = "=if(" & param(1) & "=0,0," & param(0) & "/" & param(1) & ")"
            ElseIf UBound(param) = 2 Then
                c.Formula = "=if(" & param(1) & "=0,0," & param(0) & "/" & param(1) & "-" & param(2) & ")"
            End If
        End If
    Next c
End Sub

Option Explicit
Option Private Module

Public Sub Test()
  
  Dim wbkCible As Excel.Workbook
  Dim wsh As Excel.Worksheet
  Dim cell As Excel.Range
  Dim cellDep1 As Excel.Range
  Dim cellDep2 As Excel.Range
  Dim formule1 As String
  Dim formule2 As String
  Dim division As String
  Dim adrDep1 As String
  Dim adrDep2 As String
  Dim abs1 As Integer
  Dim abs2 As Integer
  Dim ptr1 As Long
  Dim ptr2 As Long
    
  Application.Calculation = xlCalculationManual
  Application.Cursor = xlWait
  Application.ScreenUpdating = False
   
  Set wbkCible = Application.ActiveWorkbook
  
  'Recherche :
  'Dans chaque feuille
  For Each wsh In wbkCible.Worksheets
    'Dans chaque cellule de la plage utilisée
    For Each cell In wsh.UsedRange
      'Dans les cellules contenant une formule avec division
      If InStr(1, cell.Formula, "/") > 1 And _
         (Left(cell.Formula, 1) = "=" Or Left(cell.Formula, 2) = "{=") Then
        'Pour chaque dividende potentiel
        For Each cellDep1 In cell.Precedents
          'Pour chacun des 4 modes d'adressage du dividende ($L$C $LC L$C LC)
          For abs1 = 1 To 4
            adrDep1 = cellDep1.Address(abs1 = 1 Or abs1 = 2, abs1 = 1 Or abs1 = 3)
            'Pour chaque diviseur potentiel
            For Each cellDep2 In cell.Precedents
              'Pour chacun des 4 modes d'adressage du diviseur
              For abs2 = 1 To 4
                adrDep2 = cellDep2.Address(abs2 = 1 Or abs2 = 2, abs2 = 1 Or abs2 = 3)
                division = adrDep1 & "/" & adrDep2
                ptr1 = 1
                ptr2 = 1
                'Pour chaque occurence de la division dans la formule
                Do
                  formule1 = cell.Formula
                  formule2 = "IF(" & adrDep2 & "=0,0," & division & ")"
                  ptr2 = InStr(ptr1, formule1, formule2)
                  ptr1 = InStr(ptr1, formule1, division)
                  If ptr1 = 0 Then Exit Do  's'il n'en reste pas
                  'Quand le changement n'est pas déjà fait ...
                  If ptr2 = 0 Or ptr1 <> ptr2 + 8 + Len(adrDep2) Then
                    '... modifier et formule et pointer après la modification
                    cell.Formula = Left(formule1, ptr1 - 1) & _
                                   formule2 & _
                                   Mid(formule1, ptr1 + Len(division))
                    ptr1 = ptr1 + Len(formule2)
                  Else
                    '... sinon pointer après la division
                    ptr1 = ptr1 + Len(division)
                  End If
                Loop
              Next abs2
            Next cellDep2
          Next abs1
        Next cellDep1
      End If
    Next cell
  Next wsh

  Application.ScreenUpdating = True
  Application.Cursor = xlDefault
  Application.Calculation = xlCalculationAutomatic
  
End Sub