running batch file to xcopy files across workgroup

I run a Windows workgroup as my home network. My Server 2008 box executes backup batch files using xcopy via Task Scheduler. The backup drives are attached to the Server. The local one works fine.

But when I attempt to add the other workgroup machine's (it's XP) backup batch file to the Task Scheduler Library , it prompts me to add a login with which to execute it. But, it does not list the other machine in the Locations area, so I don't kn开发者_运维百科ow how to specify that account. I use the same login values for both machines, but they're created locally on each machine. I have tried typing it in longhand but it fails with an error to check the Location.

I don't want the hassle of creating a domain just for this one task.

QUESTION: how can I do this in a workgroup setting?

THANKS