Setting up a home proxy server


Hi Guys,The problem i've been facing is that my company recently has set up websense internet filtering to block out most of the popular websites including most(all) proxies...Now, I have a home computer connected 24x7 to internet...I was thinking on the lines if there were any way to set up my home computer as proxy server. It would have been easy task but another problem is to connect to Internet in office, I already have to connect via office proxy (requiring authentication), so I can't just put in my home computer IP address in browser proxy settings...Anybody got any idea, how this problem can be overcome ? I've got Windows XP running on home PC btw..Regards,