This is not a direct answer to your question, but more of a simple alternative.  If you enter the transaction directly into the ledger accounts and use the account totals to balance the checking account on another area of the spreadsheet, you'd have a checking account balance and a list of car payments.  That's one way of doing it if you do not know the more advanced Excel functions.  Your way would be better in the sense that all the transactions could be entered in the same location. 

I wish I knew half the things Omar knows about Excel.  It would probably pay to take time to learn.  Some of those tricks would probably come in handy with all the new 1099 requirements.