Excel 2007 : Formula to find discrepancies

Alright. I got a stock file uploaded... Stock.xlsx

Instead of going through the 55,000 rows in this excel file, I would love to crunch a formula that would lookup the policy number and make sure that the SUM of the End balance of 2009 along with the transactions throughout the year equals the End balance of 2010.

What I have done thus far is go through the policy numbers, insert 2 lines after the group of policy numbers, manually SUM them, and if they didn't match what the End Balance in 2010 was, I highlighted them. There are some policies that just have a beginning and an end and if they don't match, I highlight them. Any highlighted portion, another department is going to investigate them.

For example, A2:A29 is policy 10020000. A2 is the beginning balance and the Sum of transactions in between and beginning balance equals what the 2010 End Balance has on its books, so we're good on that one. The next one I have highlighted does not match.

Is there any such formula that will prevent me from doing this tedious work? If you need me to submit more information so that you can follow along, then please say so. Thank you!!