Return PO with proforma invoice - price determination

Hello,

I've got a specific question regarding the return PO process to third countries with a proforma invoice.

That the process:

- return PO is created, vendor is based in a third coutry

--> we have a customs process

- return delivery is created

- we create a proforma invoice in order to start a customs process with ATLAS

--> my question is: is there a way to copy the prices from the return PO into the proforma invoice with standard functions?

I'd like to avoid defining a new copy routine.

Regards.

chris