i have a program which looks at the header of a row and colum, then read's
the name in both headers joins the together into one word,, then looks on
another sheet to find cells containing matching data and adds the value in
the next cell

current formula is

=SUMIF('Formulas '!$C:$H,$B155&BX$81,'Formulas '!$H:$H)

as their are about 30,000 of these formula on the page is their a formula or
function which will do the same job but is not so memory hungry (takes about
5 min to calculate the ranges)