Proxy... through proxy ;)

ok, in my company i have a proxy that filter some url (yea, i know ;))
It was more then 7 year that i made a ssh tunnel with my linux machine, at work i used putty and redirect the internal squid proxy... it work very well!

Yesterday the sysadmin has made a "content port filtering" and block all the port that reply with something different from "HTTP..."

The idea is to expose the squid server and connect it through the proxy of my company. I suspect that squid reply with "HTTP", so it should not blocked... how can i connect under windows to the squid server through another http proxy?