samba - Jan 2004 - Listing users in samba backend from win client

I have samba3 and LDAP backend. Should it be possible to list the users 
in the samba backend? What i mean is,

1. I log in the XP client which is part of samba  domain
2. I select properties from any file or folder
3. I go to the security tab and I want to add an user to the list
4. Clicking 'advanced' gives me the 'find' button to show
user&groups
on my domain
5. Win client asks me to authenticate with administrative privilages to 
my samba machine
6. A list shows up showing groups and users.

I thought that now I should see the list of all my users on samba 
backend, but I see nothing else but the groups on the local machine. On 
the other hand, if I write manually MYSAMBADOMAIN\user and add this to 
the list, that user will have rights to the file/folder in question. Is 
anybody else able to get the listing of users on their domain through 
this way?

jokke h.