Define recipient from Rule in sent mail

Hi

Could any one help me, how to mention the list of recipients determined via rule resolution in sent mail.

I read in a SAP book and it suggest to define one background task to get the list of recipient from FM: RH_GET_ACTORS based upon custom rule(AC90000001). Everything is working fine. But am facing problem to bind the value from FM to workflow container. The reason is the return value of FM is in “SWHACTOR“ structure but sent mail accept experssion in AAGENT BOR.

I really appreciate your help by rewarding points

Thanks

Kamal Babu