CHAP Authentication But LDAP Authorization?

I have CHAP (PEAP) authentication working against my Samba PDC via ntlm_auth. I want to use that authentication but have users and their parameters from an LDAP DSA (that contains the SAM Samba is using). I see that a radius schema file is included and has an auxilliary objectclass. But I can't seem to find any informaiton on using LDAP for the user database but EAP/ntlm_auth for the authentication. Is this possible? -- Adam Tauno Williams - http://www.whitemice.org