Well, based on the little information you provided, I am not sure what you are asking. Do you physically want to store the users and groups in a table, or do you want to create Users/Logins based on the Active Directory user credentials?
Both are doable but the later is much easier. If you can provide a little more information we can provide a solution.
Scott Klein
Author - Professional SQL Server 2005 XML
http://www.wrox.com/WileyCDA/WroxTit...764597922.html