I would greatly appreciate any help anyone can offer on this.

Ok let me first give a little background info. I have a spreadsheet of my
raw data (spreadsheet a) it has 4 categories, account#, client name, balance
amount and a code (1-7). The code tells me what internal business category
each account falls under.

I have another spreadsheet (spreadsheet b) that takes the raw data of a. and
puts it into a neat easy to read report.

What I need is a formula that will look through the entirety of spreadsheet
a and first, determine lets say how many code 1s there are ( I know this
can be accomplished by using the COUNTIF formula) but then I need it to take
all of the category 1s it finds and then add up the balances of those
accounts.

So in essence I need it to find a certain modifier in column d then give me
a sum from column c of only those results.

I hope this makes sense.