Affect IP with script perl into freeradius

Hi i use the perl example supplied with freeradius for authenticate my user. modules { perl { module = "/etc/raddb/Test-Auth.pl" func_accounting = accounting func_authenticate = authenticate func_authorize = authorize func_preacct = preacct func_checksimul = checksimul func_xlat = xlat } If i want add a IP Address for one specific user, what is the process ? sample: All user => Use Pool of the NAS One specific user => use 192.168.50.1 (static IP) Thanks jerome