[Samba] pdbedit "user must logon to change password"

[Mathias.Wohlfarth at mw-eb.de]

When the administrator has reset the password for a user with smbpasswd, 
our users must be forced to change the password. We have tried with 
pdbedit -P "user must logon to change password -C 1", but nothing happens. 
The user can logon with the password given from the administrator and is 
not forced to change it.
Thanks for help
regards MW