samba - Mar 2001 - Make shares browseable only to valid users, and other issues

I there!

I have a network with a RH7 / samba 2.0.7 server with about 10 Win 95/98/Me
clients.
Is it possible, without having one smb.conf file for each user, to make a
share only browseable to their valid users?

Can I define that some shares require an additional password for access?

I have a problem when defining valid users to a share, based on UNIX
alternate group members.

For instance:

If foo is member from foo_group and its alternate group is foo_alternate,
why doesn't he have access to a share whoose valid users are @foo_alternate,
while he does have access to another share whose valid users are @foo_group
?

I'm solving this question setting valid users for the 1st share
@foo_alternate foo , but I think that maybe there's a better solution.

Best Regards

Lu?s Cansado Carvalho
Dom?tica SGTA
Portugal