DB lookup - is there a way ?

Hi,

I have a simple requirement and I'd like to use brfplus for that if possible

- Table in ABAP with 100k entries (legacy material number and customer material number) 

- I'd like to create a call to BRFplus which would take all lines of a document (all legacy material numbers) and get customer materials numbers

- I can do a call within the loop and execute the DB lookup expression one by one but from obvious reasons this is crazy but is there any other way ?

or maybe this requirement is not possible to implement within BRFPlus without doing any ABAP coding ?

Thank you,

Regards,

Michal Krawczyk