Not Autodetecting Proxy Settings

I've got Portable Firefox (2.0 rc3, to be exact) running on my USB thumb drive. It works fine at my house, but at school, it can't connect to the internet.

My school sysadmin has a proxy server of some sort setup (I'm not sure of the exact details - after all, as a student, I don't have access to the server). While Firefox is set to "Direct Connection to the Internet" in the network settings, I'm not able to access the internet with it (obviously, because of the proxy server).

"Auto-Detect Proxy Settings for this Network" doesn't seem to work either, for some reason. It's rather hard to troubleshoot, seeing as (as a student), I have very limited access to system settings. Without having access to the IE connection settings dialog, and no access to the system registry either, any way I can get Firefox to connect to the internet correctly?

I considered writing a simple app that would just go pull the IE proxy settings out of the registry and write them to a file, so I could configure the proxy server manually, but it seems like there should be a better way... But, if you guys don't know of any other way to get this working, anyone know of a good Java library for reading the Windows registry ?