Need Invoicing Example!

[tklingman]

I'm not sure is this is the best folder in which to post this message but I couldn't find one that seemed to fit this question!

I am looking for an invoicing example (either article, freeware, or shareware) that includes balance forward, partial payments on outstanding invoices, and calculation of finance charges on outstanding balances.

All the examples I can find on the Web are very simple invoicing that is either point-of-sale or does not use balance forward or finance charges.

I have some thoughts on how to approach this project but it would help me tremendously to see how others have attacked this problem!

Thank you very much!