A vendor has been invoicing with an incorrect PO number

Hi all,

A vendor has been invoicing with an incorrect PO number since July 1st 2007. I need to

Identify how to have all invoiced amounts, from July 1st, 2007, moved from 1 account to another.

The PO info is:

710051(Grover, Umesh) - Original PO which should NOT have any invoices posted after July 1st.

710056(Grover, Umesh) - New PO, which should be used for invoicing, from July 1st thru December 31st, 2007.

Please provide the steps necessary to accomplish this task.

Thanks and Regards,

Kumar