What is the affect on PMAC if you run create acccounting in final mode multiple times in a period?

Users wish to see shipment reports each weekly with out the costs changing each time they are re-run.  For example:  Week1, lot 123 for item A ships to customer.  Current item A cost (after actual cost update)is 5.00.  Week 2, another lot (lot 345) ships to the customer.  The current item A cost (after actual cost update) for item A has changed to 5.50.

User wants to see report as:

Week       Item      Lot       Cost

 1                A          123     5.00

2                A           345     5.50

Can this be done without causing month-end closing problems?