Cisco Wireless :: WCS 5508 Accessing Users From User Site Database

I work at a campus and use the WCS to control access to my network for staff and only internet access for students.  The Staff are assigned Username/password thru active directory and the student uses another SSID with only WPA --a password for all.  I was tasked with adding more securing for students -- by adding a user/password.  I do not want them connecting to my Active Directory for two reason--security risk and I have too many to input (over 1000).  So, I wanted to use our internal database to validate users.  I create a webpage with "WebAuth" that opens my logon page from my site and validates the login fields against the database.  It works and this allows the user to navigate thru my website but not outside the site. If they try an outside url it redirect them to my logon script.  I now understand why, so I'm looking for code I can add to my logon page that would allow me to redirect me to the controller's (once users are authenticated by my database) to call the WCS controller so I can enter a preset username/password so the policy management file would allow them access.  I presently use "External" and don't know if "Custom" would work. Finding a way in using a database instead of adding one person at a time?