IAS extension dll for using sql server as radius authentication

Hello. Im searching information about any .dll or more specifications about the "IAS extension DLL" speaked in this url:

http://technet.microsoft.com/en-us/library/cc757302(WS.10).aspx

We need some way to connect the IAS with a MS sql server, for the web Citrix (Radius).

As i saw, the only way is deploying that dll with the specifications above (there is no free dll on internet). But i think we are not enough skilled for that task, as we have never worked with radius, neither with eap or other encryptions. We are "so common" C#NET developers.

Any suggestions?

Thanks.
Paul.