You can't do the domain thing. However Microsoft produces a Microsoft User AuthenticationModule for Macs. (M UAM) so that Apples can log into w2k and mount SMB shares (windows file sharing.)
Also there is Appleshare support for W2k, but personally I prefer SMB.
It may be possible to do domain authentification in the traditional sense using the netinfo stuff, but I don't have a Idea how to do that.