Encrypt password with EAP auth

Hi, I use Freeradius as authenticator for our wireless Windows XP users. I successfuly configure communication and users can authenticate (eap module). I use MySql database where I store username and params. I want to use our existing database of users but our database uses function ENCRYPT() (in MySQL) to store user password. I can't configure freeradius to use this encrypted password. Can you help me ? Lubomir Vogl