Password Expiration with Samba

I have windows 9X clients logging onto a Samba domain on a Unix box. Hence all users have a username on the unix box.
If i want to employ password expiration on this box how can i let the windows users know that their password has expired?
NOTE:they only connect via the domain logon, they do not use telnet to logon. In my experience if a password expires the domain logon will continually fail with invalid password but if you telnet to the unix box you get “your password has expired please change it”.

So how can i use password expiration on the unix side with windows clients and let them know about it?