If I am not mistaken I should do the following:
In "/etc/samba/" I should create a "smbusers" file and add the line: "root=Administrator"
In the "smb.conf" add the line:
"username map = /etc/samba/smbusers"
Ok, thats the info was looking for
I still have one question
and since you just add Administrator to smbpasswd it shouldn't hurt anything from the domain users, unless you completely join the box to the domain.
What do you mean with "completely join the box"?