how fetch sales order number and item in characteristics directly when doing goods receipts PO

Hi

I would like to  fetch s ales order  number and item number in characteristics directly when doing goods receipts to PO,

I have created characteristics  for  sales order and item then in additional data assigned AFPO - KDAUF/KDPOS and while doing goods receipts values not copied to batch characteristics,

please guide how to achieve at the time production order goods receipts.

thanks

Mohan M