You can use rsh (not secure) or ssh (more secure). By the way, if you use halt with the "-f" option, you do not need to disable cluster. That way, cf will get enabled automatically again after a reboot.
For rsh, you will need to setup a host that may access the filer:
options rsh.enable on
options rsh.access host=<ip-addres or hostname from which you run the script>
Then in the script, you can run the commands like this:
With rsh you don't need to provide the password (that's why it is not secure - no password required and no encrypted network connection). Oh, and on Windows 2008/Vista and higher you don't have rsh anymore.