dialing restriction on analog set--FXS port

[lullar]

Hi i have some routers 28xx series...i have few extensions connected with FXS port..these routers are connected with a avaya PBX using E1..The analog extension connected at FXS use avaya PBX PSTN lines for dial out...Can wee restrict some dialing digits on these analog extension connected to FXS port through CISCO router???
I mean is there any configuration/translation can be done in CISCO router to restrict analog extension being dialing IDD calls??

Thanks