Purchase Receipt and PO fulfill

Hi,
I have a problem with purchase receipt (PR).

When I receive a truck, materials (identified by batch number) in the delivery note can fulfill different Purchase Order (PO), so I can’t create a PR from Purchase Order page, because the receipt will fulfil only that specific Order.

Instead if I create the PR from Stock page, when I insert the batch in the rows Item code the field of PO is not available.

I Need to specify for all batch what PO and position in the PO that order will fulfill. How can I do it?