Following on (hopefully you can help me Ardus)

I can't get it to work in context

If in cell AF3 is 0703

currently the formula below is
=SUMPRODUCT(('[Incidents period0703.xls]DATA'!$G$8:$G$2000=$C8)*('[Incidents
period0703.xls]DATA'!$W$8:$W$2000="Mainline"))

but how can I change this formula to depend on the contents of AF3?

ie if AF3 was 0704 the formula would read
=SUMPRODUCT(('[Incidents period0704.xls]DATA'!$G$8:$G$2000=$C8)*('[Incidents
period0704.xls]DATA'!$W$8:$W$2000="Mainline"))

Many thanks in advance