Credits - Projects URGENT REQUEST

In Projects Module, I need info on the following scenario:

Create new project

Create Item requirements. From Item Requirement, Functions, Create Purchase Order,

Post PO Packing Slip.

Post PO Invoice.

Create Customer Proposal.

Approve Customer Invoice

Post Customer Invoice.

Assume the Customer Invoice is for a quantity of 1, with a price of 500 USD.

Assume that the PO created has the SAME quantity of 1, with a cost of 500 USD (a pass thru item)

At this point, what would be the best way to accomplish the following:

Assume you want to do a partial credit of 75 USD.

1. You want the partial credit to be reflected on the PO - using the same PO.

2. You want the partial credit to be reflected on the Customer invoice - may or may not be same Customer Invoice (remember the first customer invoice is already posted).

3. You want to be able to see IN THE SYSTEM the link between sales order (or customer invoice) and purchase order. OR in SOME screen within projects.


Very much appreciated !!!