[Samba] password changes with ctrl-alt-del

[Geddes]

Currently I'am using samba for file sharing. My smb.conf file is basically 
setup as default with a few minor changes. Therefore, my samba server is 
not part of a domain. Right now users can map the samba shares with 
windows XP... With this type of setup is it possible for them to change 
there smbpasswd using ctrl-alt-del? If so any examples or hints on how 
to set this up would be great. 
 
I have tried a few things and the only way I can get this to work is to 
make my samba server a PDC and have the workstations join the domain. The 
version of samba I'am using is 2.2.7a.

Thanks