Custom Data from SAP CRM to SAP ECC

Hi all,

i have been developing an enhancement on CRM middleware to pass custom data from SAP CRM to SAP ECC using the following link :

http://wiki.scn.sap.com/wiki/display/CRM/Enhancing+the+CRM+Middleware+Example2

This link is a good guide,but i have a doubt about process SMOUTIL2 used to enhance structure T_BAPIMTCS on CRM side.

Is it enough to append custom additional data to this structure (T_BAPIMTCS)? Or have i to enhance standard BDOC structure called "BUS_EI_MAIN" also (component PARTNERS)?

Will this additional data available in SAP ECC system in BTE?

Thanks in advance.

Regards.

Dario.