Raising User rights to Admin during logon, then lowering after logon has finished.

Hi,

This is the set-up that i have

Windows 2000 domain
500 Roaming user profiles
Windows 2000 Terminal Servers

I have been told by someone that it is possible to raise a users security from a normal user to a power user or even administrator during logon, then be able to lower the security again after logon.

My questions are as follows

1) Is this actually possible?
2) If it is, can someone tell me how to do this, e.g group policy or send me a link.

I want to try to do this so i can do some things that i would not normally be able to do with users during the logon process.

Any help on this would be much appreciated.


Thanks