I have multiple spreadsheets in multiple files I am trying to run IF(AND) forumlas on.

EXAMPLE:
I have a spreadsheet of bank transactions from multiple banks for a company: check date, check #, payee, amount. I have other spreadsheets containing the same info provided by the bank, data being divided into each spreadsheet by bank.

I want to compare the spreadsheets' info for accuracy for the info provided by the company. COMPLICATION: there are not always unique identifiers assoicated with the transactions (missing check # or date) and there are duplicate check #s and amounts.

TRIED: I ran vlookups to compare the check #, amount and clear date. However, since these were run separately I am getting false positives from the duplicate info.

GOAL: I want to run a query that will tell me if the matches from vlookups came from one column. OR, run a query to compare "IF the check # matches, does the amount in the same column match also".

Ideas?