two newbie questions

[Pupeno]

-I would like Windows 98 clients to read user.dat (user.man?) from the
profiles directory on the server... in the texts I´ve read it appear to
be done automaticaly, but I copy my user.dat and user.man to the server
and my W98 doesn´t read it.
Do I have to configure something on Samba ? or on my Windows 98 ?
-I would like to know if there is any way to specify which user can log
in in which computer, is it posibly ?
Thank you.
				Pupeno

PS: Thank you to the developers of Samba, you´re doing a great job!!!