Operation Quantity in Confirmation Screen

Dear Friends,

I am working in Process Industry.In COR6N confirmation screen on GOODS MOVEMENTS tab we are giving the raw material consumption for the order.Here we can enter the other materials which are not in BOM. My requirement is, i don't want to allowed to enter the materials other than the BOM component. I want to block the entry of other materials.Is there any setting for this. How to do this?

Your valuable suggestions are very important for me. Thanks in advance.

Reagrds,

Prafulla