1896 Amount owed script/not website

I'm looking for someone that will make a cold fusion script, that will show the amount of debt that someone owes me, adding in interest rate owed. ORIGINAL AMOUNT OWED: $437,127.50 Interest rate 6% auto calculated The ability to add payments, and surcharges by dates ONLY SHOW Balance due: $______________ Requirements: 1) Must be in cold fusion. 2) I do not need a complete website, just the script. 3) MUST allow someone to copy html code to post the current amount due on their own website. 4) The amortization must be accurate, anotherwords, if payment is made, or a new fee applied, the amount showing due should begin on the new balance, not the previous balance. 5) Information would pull from access table. The only information I want people to see is the final total owed. Similar to the "national debt" calculators that you see.