Issue in Payment Terms

Hi

I have an issue pertaining to FI-AR in Payment Terms. We have a requirement in which we would like to define payment terms based on both document date and posting date. If suppose the billing for invoice has been done on 1.1.2009, and if the payment is recveievd within 4 days of billing, the system should pass automatically a credit memo of 1.25% and should also check that the instrument date should be between 1st and 4th. Similarly, if payment is recieved within 10 days of billing, then system should pass a credit memo of 0.5% and also check that the instrument date should be between 1st and 7th. Similarly, if the payment is recieved between 10th and 15th, system should pass a credit memo for 0.25 % provided that the instrument date should not be more than 12th.

In case, there is a credit balance in customer account (payment recieved in advance), system should pass a discount of 1.25% as a credit memo on the balance or sales order value which ever is lower.

The system should accumulate the discounts passed and pass a single credit memo on a periodic basis. System should not book the cash discounts in the way, it does at the timne of booking incoming payments for customers

Regards

Sanil