samba - Sep 2007 - Disable share mapping without joining domain

Hello everyone!
In a "normal" BDC with shared directories, a user can map a drive even
if
its client machine hasn't joined the Domain. For that, the user just need to
have an account/password in the domain for doing that, and the Windows (or
Linux) will ask for the user/pass for that share.

But I don't want that to be done, I would like to allow only users that have
actually JOINED the domain to map drives, and consequently disable any
attempt to map drives from users that are not in the domain (even if this
user has an account in my domain controller).

Is there a way/possibility for doing that access control in Samba?

Thanks in advance for any help/idea!

Best,

Steve