Update Zfields on relationship Contact Person

Hello,

Does anybody knows how to update values for Z fields created with EEW on Relationship (table BUT051)?

what BAPI can be used here?

I found structures INCL_EEW_BUT051 and INCL_EEW_BUT051_x in SAP CRM. First is in table BUT051 where I want to fill my fields. Second I can not find anywhere (in any FM or table).

There is sap not 807493 pointed in this include but it does not exist.

Regards

Radek