I think that if you want to escalate privs, you have to do exactly that. There are a number of tools out there, like Pass the Hash Tooklkit that will do this for you. The user you are escalating to may have to be logged on. You can also code your own with API hooking. Still, I think you would have to have the higher privileged user already logged on.
You can also trying running a Startup script through Group Policies. It runs on computer startup, not user logon. This script would run under the Local System account and will not have access to other Network nodes most likely.