A pretty simple VBA problem in excel

I am trying to create a simple module to input either P1 or P2 in
selected cells.

If the column selected is D, E, F G

D and E should equal P1
F and G should equal P2

This should work for any combination such as if only D or G is selected
D = P1, G = P2.

I have the following worked out but I cannot get it to fill in the
cells properly, if I only select a single cell it works fine, but if I
select D - G it fills it all with P1.

code:
Sub CellFill()

If (ActiveCell.Column = 4 Or ActiveCell.Column = 5) Then
ActiveCell.Value = "P1"
Else
ActiveCell.Value = "P2"
End If

End Sub
/code



Any help is appreciated