CO-PA derivation rule, table lookup to VBRP

Hallo,

In the transaction KEDR I try to maintain a lookup to the table VBRP - "Billing Document: Item Data". To select a row in this table I need to fill two key fields: VBELN - "Billing doc." and POSNR - "Item".

In CO-PA I have this content in the technical fields RBELN - "Reference document" and RPOSN - "Reference item no." Unfortunately these technical fields cannot be selected as CO-PA source fields for a derivation thru table lookup.

Is it possible to use the table VBRP for a table lookup in the characteristics derivation in the transaction KEDR?

With best regards,

Robert