Using Samba to authenticate PPTP?

[Patrick J. LoPresti]

We have a Windows NT Server which provides PPTP service.  I want to
move its authentication database to a Samba PDC.

My question is, how do I tell Samba that a particular account is
permitted dialin access?  In the NT "User Manager for Domains", I do
this by checking a box.  Does that checkbox just add the user to some
magic group, or is there more to it?

Thanks!

 - Pat