mac and username

Hi all, first time posting here. Is it possible to reject a user based on UserName and Calling-Station-ID. What I would like to do is reject specific users from logging in on specific machines. And if yes, if it`s possible, an example of the sql query or config would be appreciated. Thank you all JP -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.1.407 / Virus Database: 268.13.0/464 - Release Date: 2006-10-05