How to archive and purge fully invoiced Purchase Orders in NAV 2009

We are using NAV 2009 R2. Our purchasing agents have been using the "get receipt lines" functionality rather than invoicing from the PO for some time now (see user comments at the bottom of the post to see how they are invoicing purchase orders).  My understanding is when you invoice in this way, the system does not Auto-purge the purchase order as it would if you were invoicing from the PO. Because you are not on the Purchase Order itself, you are also not giving the agent an good stopping point to archive the PO before invoicing.  These old fully invoiced purchase orders are now clogging up drop-down lists and generally making day-to-day work in the purchasing system difficult and clumsy.  We are searching for a way to archive and purge in mass.

Under "IT Administration/Data Deletion/Purchase Documents" we have found a number of utilities such as "Delete Invoiced Purchase Orders". Problem is there does not appear to be an "Archive before Purge" option. The tool simply deletes the purchase orders that qualify.   

Q: How can we purge, making sure the final state of the PO has been first archived?  I have not found a BULK archive utility we could possibly run before the purge.  We do have developers on staff that may be able create a customized process, but before we spend time/money on this, I wanted to be sure I wasn't missing something obvious and easy.

Please help! :)



User Comment below:

Usually when I post a PO from the PO the PO will disappear from the system. But I have learned a new way to post a PO by going to Purchase-Order Processing-Invoices. Then I create a new invoice and pull in the receipt lines from PO by functions get receipt lines. After I post it, the PO does not go away like it use to do in the regular posting from the actual PO. Is the only way to make it go away is to archive the PO and delete it?