Combo en cascade

Private Sub ComboBox3_Change()
Set mondico = CreateObject("scripting.dictionary")
For Each c In Range(f.[D2], f.[D65000].End(xlUp))
  If c = Me.ComboBox1 And c.Offset(, 1) = Me.ComboBox2 And c.Offset(, 2) = Me.ComboBox3 Then mondico(c.Offset(, 3).Value) = c.Offset(, 3).Value
Next c
Me.ComboBox4.List = mondico.items
Me.ComboBox4.ListIndex = -1
End Sub