Really Need Help Putting Discounts in a Loan Spreadsheet

[Skint]

Alright so I've created a spreadsheet which has a data sheet containing a list of loans owed to a loan company, and a stats sheet containing various statistics which are generated by information on (and affect calculations made by) the data sheet.

On the data sheet, the loan amount, loan length, annual interest rate, and discounts are inputs. The total without discount and the Monthly Payment are outputs which I calculated.
On the stats page, the possible discounts are both inputs, as are the two dollar
values under “Loans over”. Everything else is an output, which I calculated.

(here's a screenshot of what I have so far)

http://img.photobucket.com/albums/v465/Skint/Untitled-2.jpg?t=1268699157

Outputs I calculated were:
Total w/o discount is the total which would be repaid on the loan, assuming no discounts.

Monthly Payment is the amount that will be paid per month on the loan, assuming the same payment every month. (which applied discounts)

Total Owed is the total owed to the loan company,

Expected per month is the amount of payment expected per month. It is the sum of the “Monthly Payment”column.

The Loans over section calculates the number of loans which are worth more than specified values ($500 and $5,000 in the example). This is calculated based on the loan amount, not the total that will be repaid.


Alright, if you're following me, I'm having trouble figuring out what I'm trying to do next, I need to implement a generic support for discounts. That is, enabling new discounts to be added simply by adding another line in the “possible discounts” section.


If this makes any sense to anyone, please help me, if this is unclear and you need more info, please let me know.

Thank you in advance.[img][/img][img][/img][url][/url]