Formula to find multiple matches & then sum result from another column into another sheet!

[justmeok]

Hi All

I have spent so much time trying to figure this out on my own with a spectacular lack of success

I want to lookup a variety of codes and then sum the balances from another column if code matches are found. There are 12 codes that I want to combine into one cell on another sheet in the same workbook. Not every code will appear each month so the formula needs to allow for no match to be found but to still combine the balances from the codes that are there.

I don't think I've done a good job of describing what I need so I will upload a sample spreadsheet that hopefully will make it clearer! The data on the sheet named LY Jul Data is exported from another program and I don't want to have to make any changes to the format etc but just use it as it is.

I have played around with array formulas, sumproduct, sumif, isna and combinations of them all but still can't figure out what to do!

Note the formula must work in Excel 2003 please.