shutting down all computers on network

Hello
I had to replace my battery backup,an APC XS1000, it has a USB hookup instead of the powerchute card. I asked APC and was told it could not shutdown other computers on the network and to buy another UPS. If I use the default power options that comes with XP it gives me an option to run a file before it shuts down. I have searched the web for Shutdown programs but I have to click on a button to shutdown the other computers instead of the command line. I have used a one click Shutdown program on the other computers running Win98 for yeard but it doesn’t power down XP. How can I activate the program from the XP computer over the net?
Do I need a batch file and then put it on each computer to shut them down?
Any help will be appreciated
Thank you