[Samba] Samba and Windows Domain Usernames

[Marco Ferra]

Hi to all on the samba lista.  I'm new on Samba and on the mailing
list so forgive me for any misunderstading that I may commit.

I have a Samba daemon running on a OpenBSD machine with only a
directory shared.  Anyone can read and write on that directory.

However, on the same local network there are various Windows machines
and the users of those machines are users of a Windows Domain.

Is it possible (and if yes, how) to define on smb.conf that certain
usernames can read/write some shares, others can only read other
shares, and Windows prompts for the combination username/password for
other shares?  Those users that logon on the Windows machine should'nt
be prompt again for a password on the samba share (if in fact they
have permission to access that share).

I have read the Samba users manual and some examples but didn't find
anything about this.

I hope that you can help me, and my sincere regards,

Marco Ferra