Comment apliquet une macro a des cellules

Option Explicit
Private Sub Worksheet_Change(ByVal Target As Range)
Dim isect As Range, c As Range
Dim ligne As Integer: Dim colonne As Integer

For ligne = 3 To 1094 Step 3
For colonne = 3 To 35 Step 4
Set isect = Intersect(Target, [BT3])
    If Not isect Is Nothing Then
        For Each c In Target.Cells
                c.Offset(0, -24) = IIf(IsEmpty(c), ("Mr"), Empty)
                c.Offset(0, -23) = IIf(IsEmpty(c), ("Durant"), Empty)
       Next c
    End If
     Next colonne
   Next ligne
End Sub