Exécuter macro sous 2 conditions

Sub form()
Dim lig As Integer, plage As Range

    Application.ScreenUpdating = False

Application.Calculation = xlManual ' accélère l'exécution
Application.DisplayAlerts = False




For lig = 3 To 100
  With Range(Cells(lig, "A"), Cells(lig, "P"))
    'si la ligne n'est pas vide on l'unit à plage
    If Application.CountA(.Cells) Then _
      Set plage = Union(IIf(plage Is Nothing, .Cells, plage), .Cells)
  End With
  
  Range(Cells(lig, "M"), Cells(lig, "P")).Select 'fusionne MNOP
  Selection.Merge
 

Selection.EntireRow.AutoFit ' hauteur ligne automatique
Selection.EntireRow.RowHeight = Selection.EntireRow.RowHeight + 10 ' + 10 pixel
If Selection.EntireRow.RowHeight < 25 Then Selection.EntireRow.RowHeight = 25 ' hauteur de ligne 25 mini


 
Next

'efface la MFC et les bordures
With Range("A3:P100")
  .FormatConditions.Delete
  .Borders.LineStyle = xlNone
End With

If plage Is Nothing Then Exit Sub    'si tout est vide...
    
With plage
  
  'crée les bordures
  .Borders.LineStyle = xlContinuous
  '.Interior.ColorIndex = 43
  .HorizontalAlignment = xlLeft 'alignement texte
  .VerticalAlignment = xlCenter
  .Locked = False 'protection cellule
  .FormulaHidden = False
  
  'MFC 1ère condition
  .FormatConditions.Add Type:=xlExpression, Formula1:="=CELLULE(""row"")=LIGNE()"
  With .FormatConditions(1)
    .Font.Bold = True
    .Font.Italic = False
    .Font.ColorIndex = 3
    .Interior.ColorIndex = 6
  End With
  
  'MFC 2ème condition
  .FormatConditions.Add Type:=xlExpression, Formula1:="=MOD(LIGNE();2)=0"
  .FormatConditions(2).Interior.ColorIndex = 34

   'MFC 3ème condition
  .FormatConditions.Add Type:=xlExpression, Formula1:="=MOD(LIGNE();1)=0"
  .FormatConditions(3).Interior.ColorIndex = 36
  
 End With
    

     
    Application.Calculation = xlAutomatic
Application.DisplayAlerts = True

End Sub