proxy everyone

hi list! i'm setting up my freeradius architecture with a single proxy and multiple servers; here's my scenario: freeradius server # 1 -> my own server [realm local.net] freeradius server # 2 -> external server [realm ext.net] freeradius proxy -> i know everything about users i proxy towards my server [# 1] but i don't know anything about users i proxy towards external server [# 2]. i would proxy every_username@ext.net just to log requests. so this is my question for you: can i use rlm_realm to proxy an entire realm without knowing the usernames just to trace auth/acct requests? or i'm crazy at all? i hope you'll understand my question......... ;) thanks, duffy