C++ RADIUS client sample code



I have a C++ program running on a Win2K Server that currently uses ADSI to
authenticate users against an LDAP Membership Directory.

I need to begin authenticating these users against a RADIUS server also.
Can anyone tell me if ADSI can be used for authenticating against a RADIUS
server, or suggest another interface to facilitate RADIUS authentication from
a pre-.Net C++ client application?
.