Reminder invoices on unpaid accounts

[David Lark]

Fellow GC users:

When a customer account is not paid in full, I have the need to send an 
additional monthly invoice. This invoice would ideally take the 
following form:

  * New line items (posted to accounts receivable).
  * Subtotal for the above.
  * + Amount due from previous invoice(s).
  * - Payments received.
  * + Interest on unpaid balance (posted to A/R).
  * = Total due now.

Just creating a new invoice with the past due amount entered as a line 
item would result in the past due amount showing up twice in A/R. The 
only way I can think of to do this is to create the invoice, and negate 
the original amount in a subaccount, perhaps called "Delinquency 
Rollover" or some such.

It seems as if the A/R capabilities of GC aren't quite there yet. Or 
perhaps my brain is what is missing some features. How do you deal with 
this situation? All ideas will be welcome.

David