If the PO's are inside EPDM and their datacards are populated with the relevant metadata (i.e. PO#, date, supplier details, order value, etc.) you can run an add-in but I have investigated this but can't see a way to run a template to "copy" this info to another file.
On that note, I just finished writing a vb.net add-in to do "almost" the same thing.
After investigating what is involved to make an EPDM template do this and not finding a way, I wrote the add-in.
See my site for contact details or PM me.
Hope this helps,
Tim Webb, CEPA
Although it was really written for handling files with external references, I think you could use the "Copy Tree" command to accomplish what you want to do.