Idoc for CRM product and relationships

Hi,

I am looking for an IDOC for product in CRM that has also a structure representing the relationships with other products.

The transaction is COMMPR01, chose a product (of type materials), on the top of the page there is a button 'Relationships', the Accessories tab, there you can enter other products, I need an IDOC that represent this structure.

Thanks,

Naama.