Subcontracting PO Scenario

Hi ,

I am having a scenario in which the 101AA material is to send out for some small work to another vendor and it is coming as 101AA itself in the system. but 101aa is having a BOM and when ever i am creating a subcontracting PO with Item category L it brings itself the components also. though i tried to remove the special procuremnt key 30 also from the parent component also.

Please advice how can i carry this operation where the material is goinng in same code and also coming in same after a smal work.

Help.