Well I was going to suggest PUList or another NT/Win2K ResKit utility, but I am hughly doubtful these will work under WinME. If you installed a Telnet service or something like the Remote Command Manager under Win2K, then you could open a remote session on Win2K and use "kill" to kill any processes.
I am unaware of what remote process management utilities are available for WinME. WinME may have a remote "kill" utility in its ResKit, but I haven't played enough with it to know for sure.
VNC may not give you the access you need for such a thing either. typically when a machine locks up like you describe, keyboard and mouse control are unavailble and the graphic interface is frozen. A cmd line session is what is usually needed to do any administration.
Two suggestions for now until someone with better knowledge can provide something more definitive:
1. Check the WinME CD for additional tools and utilities, even a ResKit. I don't have WinME readily available at the moment, so don't know what is on the CD.
2. Try searching on several shareware/freeware sites like tucows or winfiles.com for the type of tools you are looking for.