I have a simple spreadsheet with 4 columns the first 2 columns have user
entered values.

Column 3 & 4 have "=A4*B4" & =SUM($C$4:C4)/SUM($A$4:A4) respectivly and this
works fine.

What I want is Excell to automatically add thes formula when I enter values
into row's 1 & 2. I know I could autofill the formula all the way down but I
want excell to do it as I go. As I said I did get it working but I don't know
how.