Proxy's problems

Hy guys.

My problem is a little bit complicated...  I'm trying to write a small browser for my company..

Let's say that we have a LAN , with a server connected to INTERNET. On this server , there is a Proxy server.

Now , the only way a client can connect to internet is through that proxy.

Now , if I do a GET www.somesite.com/index.htm , I get an response like of HTTP 305 error , saying that I must use proxy.somesite.com

Now, how can I connect to that proxy ?

Remeber that I have access only to my LAN's proxy. So , I must tell him to connect to proxy.somesite.com and issue an GET www.somesite.com/index.htm

I understood that is something called PROXY CASCADE.

Now , my question is how can I do that ?

I'm using sockets for network programming....



Thanks