I was playing around with WMI to try to get this to work, but I've had 3 issues.
1: Anything I start doesn't show up with an application window on the remote system.
2: Most of the system's I've tried i'm getting access denied messages on.
3: How do I pass command line arguments O_O.
Not sure what you are doing but maybe take a look at the SysInteral's PsExec from Mark Russinovich.
Instead of trying to make remote WMI calls (and dealing with the security issues that arise from it), see if you can use rexec, which handles its own authentication. You can find a daemon service for NT, 2000, XP, 2003, etc. in the MKS Toolkit.
By default, services do not have access to the user's window station; checking "Log On > Allow service to interact with desktop" will enable this. (Though on Server 2008 and Vista, these windows are still forced to a separate, non-user window station regardless.)
This Hey, Scripting Guy! article explains #1 and suggests a workaround.