fill cc addresses upon selection of form id from drop down

Hi All,

I have one requirement in CRM where when i am creating an email as a follow up for the complaint doc the CC address (Carbon Copy) email id should be defaulted i.e when i select any form id from the drop down it should papulate the id in CC.I see only CRM_IM_DATA_MAIL  BADI getting triggered and i tried implementing this BADI but it dint work.Plz let me know how should i achieve this functionality.

I did populate the CT_Attribute itab put no result.Plz let me know how will the cc mail ids get populated when i select some form id which are available in the drop down.

Thanks,,,