Proxy and clear-text password

Hello! I have set up my freeradius 1.1.3 server to use proxy feature. User@domain1 are redirected to the radius2 which store the usernames and password for that user. It seems that my nas is sending encrypted passwords but radius2 only accept clear text passwords. And my radius1 is proxying the request of the user@doamin1 with encrypted passwords to radius2. What can I do to send the clear-text passwords to radius2? Thanks. Luis