samba - Mar 2006 - Preventing users from logging in on certain conditions

Hi,
 
I'm trying to setup samba so that if the user's home folder and profile
isn't available on the linux server, the user is prevented from logging in.
 
I have tried using the preexec command with the preexec close option on the
[netlogon] share, but this just forces windows to carry on the login without
using it's login script.
 
Is there a way to have a script run at the time when a windows client
authenticates to samba, as the domain controller, and the script refuse the
user authentication?
 
I'm using samba 3.0.10 on RH ES 4 and Windows XP SP2 on the clients, with
LDAP authentication from samba.
 
Any suggestions?
 
Dave Smith
System Administrator
m/v Africa Mercy, Mercy Ships
Tel: +44 (0) 191 428 6434 ex 254
www.mercyships.org <http://www.mercyships.org/>