You know they setup a proxy to keep you from doing this right? You really should talk to your administrator. Violating network security policy is usually grounds for termination or other distasteful actions.
Anyway...
The proxy must be configured to allow ssl connections. If you can https to a web site then you know that you can at least attempt to tunnel your ssh through the proxy.
Go try an https site. I'll wait. Ok. Back yet? How did it turn out?
Assuming you were allowed to https then we'll move on.
Most (as in all I've ever seen) proxies that allow ssl connections are set to only allow this to tcp 443. Don't ask why I keep talking about ssl when you are wanting to ssh.. that's a different topic. Just trust me. Anyway like I said.. the destination that most proxies allow ssl connections to will ONLY be tcp 443. Has to do with security and what not. The CONNECT method... anyway.
So?
So change your ssh server to listen on tcp 443.
You are half way there. Now you can do this the easy way or the hard way.
Easy way. Get putty and use the proxy feature. Setup keep alives. Done.
Hard way. Get a program that will redirect connections through a proxy. SSH through that. Manually setup some type of keep alive or possibly enable it on the remote sshd.
I've done both. Finding a linux based proxy program to create a local tunnel that you point ssh at will be your only real challenge (hard way). This may help or not:
http://www.linuxlinks.com/Software/N...g/Tools/Proxy/
-b