I managed to create a macro to show the following:

If (I3<>0,I3*G3,H3*G3) and this repeats itself for cell N3,R3, V3,Z3 ETC.

Option Explicit
Sub Eg()
Range("J3, N3,R3, V3,Z3,AD3,AH3,AL3,AP3,AT3,Ax3,BB3,XF3,BJ3").Formula = "=IF(RC[-1]<>0,RC[-1]*RC[-3],RC[-2]*RC[-3])"
End Sub

Let me explain a bit more how this should work:

This report needs to be downloaded from an application.
The macro needs to be attached to this report so that when I download the report the macro automatically runs this formula in the appropriate columns.

Also I 'll have to populate the spreadhseet for all the rows with this formula.

The columns where the formula should sit are not blank but this needs to be catered for in the report automatically once the macro is run.

What am I missing here?

Hope you'll be able to help.

Thanks.