Business partner: how to add EKORG

HI there,

I have several hundert BP with vendor role. However the purchase org (EKORG) is missing.

I tried update by recording on transaction BP, but this does noc work since the dynpro sequence in batch input is different than in the recording.
How can I add a EKORG to the BPs?
Using a BAPI called from LSMW?

Any suggestions?

Thanks!

Andrzej