You could use something like cusrmgr [best for unique passwords] from the
Resource Kit or psspasswd from SysInternals/Microsoft. The links below
explain more. You could also use a Group Policy startup script that use the
net user command as in net user administrator newpassword but if you do be
sure to change the permissions on that startup script so that it does not
include users/domain users/authenticated users/everyone but instead has
permissions for administrators and domain computers otherwise curios users
could browse to the sysvol share and read the newpassword in the script.

Steve

http://support.microsoft.com/kb/272530
http://www.microsoft.com/technet/sysinternals/utilities/pspasswd.mspx  ---  
pspasswd

Steve

Check out the Passgen tool from Jesper's and my book, "Protect Your Windows
Network." You can download the tool free from
http://www.protectyourwindowsnetwork.com/tools.htm.

What you will probably run into if you mean you want to set the
account to a known, usable password, whether the same on all
of the machines (not the best plan in my view), the same on sets
of machines with there being so many sets your machines are
divided into, or unique per machine, is keeping track of which
machines were available and had the account successfully set
to the new password.
One approach is to use an indicator, like some reg key or file
that only admins can create/delete.  Then, your remote process
checks if the indicator exists in correct state, and it not then it
sets the password to new value.  Alternatively, you can track
the change state centrally, as in database.  The method used
will depend much on how you change the pwd, whether with
something like a WMI script, pspassword, machine startup
script, etc..

Roger