How to Add email id to CC field in Email template dynamically.

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.

Thanks.