Custom Aged A/R Report needed

A few months ago I had a request from a customer for a complex Aged A/R Report and spent many
hours trying to create it in Crystal Reports. Somewhat successful, but not enough to give them all of the results they want.

They would like to see the invoice amount, any payments or credits applied and then have
the remaining balance aged. 

 And then they would also like to group by Sales person ID.

Reference numbers for invoices and for payments and date of those transactions included; Running totals for customer and Grand totals for the report.

I can go into more detail, but I think a good first step is just to see if you think this report is \"do-able\" .!

I was only able to reflect the total amount applied to an invoice rather than each payment, and had a second issue of
not getting an accurate report if I pulled it for a prior period. When I tried to pull the report for a prior period, it did actually show me the balance for an invoice through my "AsOfDate" of the report and aged it, but additionally showed me the amounts applied in a subsequent month (that is ok, but would rather not have it on there). 

I was using 1 parameter for AsOfDate, a second parameter for the cutoff date for paid in full invoices that excluded paid in full invoices before the date provided by user, and a third parameter for Customer ID that was optional.

I sure would appreciate an expert opinion on this before spending much more time on it. Regards,
Linda Huff