samba - Feb 2007 - Change the smbpasswd from a WinXP client (without PDC)

Is there a way to synchronize changing a user's WindowsXP password with 
the smbpasswd?

I configured a basic Samba server (3.0.10) with password encryption 
enabled.  When I
created the smbpasswd file, I used the same username:passwords as the 
WindowsXP user
accounts.  After the initial connection, users can login and map the 
network shares seamlessly.

Users are required to change they WindowsXP password every 90 days.  It 
is possible to
change the smbpasswd from WinXP using the "Logon Information
Properties"
GUI.  But
there are alot of steps and some of the pre-filled fields are wrong.

Start | Control Panel | User Accounts | <username> | Related Tasks 
"Manage My Network Passwords"
Select the server in the Stored User Names and Password windows and 
click Properties.
In the Logon Information Properties window change the default UserName 
field* to smbpasswd.
Click Change...  Enter the old password and the new password.

* The UserName field is pre-filled with either "MACHINE\USER" or 
"USER@SERVER", strip-off
the MACHINE or SERVER, leaving just the USER name. 

I am looking for DOS command similar to the NET USER command
   c:\> NET USER username {password|*}                    changes the 
Windows account
   c:\> NET USER username {password|*}  /DOMAIN   does not work, since 
there's no PDC

I would like to write a batch file to keep the smbpasswd and Windows in 
synch.

TIA