Adding a realm to username with pam_radius_auth

Hi, Quick question regarding pam_radius_auth. Since you have to have a local account on the client machine using pam_radius_auth to authenticate ssh sessions, how would you go about adding a realm to the username portion of the authentication request? Reason I'm asking is because I'd like to use pam_radius_auth on a client machine that talks to a AAA proxy server. The proxy server needs to use the realm name to figure out which AAA server to route the request to. Can I specify this with the client-id option in the pam_radius_auth configuration file? Thanks, Walter