Not sure what your corporate setup is, but if you're blocked out of everything but ftp/http (like me) you can setup a ssh tunnel and connect through that.
here's what to do.
On Thinkpad, install Putty
Create tunnel from local port to your server over a port you're allowed to access.
Point VNC software to the local port
Setup the VNC server to listen on your home server on the correct port
there are millions of tutorials on the internet explaining how to do this (fyi any linux/unix instructions apply)