Wifi with Welcome message?

Hi, Is it possible to send or execute a script to a user when he authenticated thru wi-fi connection with particular NAS. Like when user joe successfully authenticated with the sql database, if he was connected with NAS IP address X, he receive a Welcome message X and if he authenticated with NAS Y, he receive Welcome message Y. Currently I have Freeradius 2.0 with authentification on a mssql database and it work and give an ip address to the client when is authenticated. Guillaume