[Serusers] how to rewrite radius request information packet before sending to radius

Hi, I have a ser system talking with radius. there is no problem with authentication. but what i realized is that, in my radius request packet: USER-NAME= user1@ip_of_ser and this radius packet goes to radius for authentication. But i want to change the radius packet. so that my USER-NAME = user1@ip_of_ser will change to USER-NAME = user1@ip_of_user1 I need to change the authentication information of the radius packet, before sending it to radius. how can i handle this? do i need avp module or what? please help me? please --------------------------------- Yahoo! Mail Use Photomail to share photos without annoying attachments.