Proxy, Tunneling & Proxy Within Proxy

Hello:

Our organization recently made it necessary for web browsers to use a proxy to access the web. The .pac file reads as such:

function FindProxyForURL(url, host) { var proxyOn = "PROXY 10.2.2.254:8080"; var proxyOff = "DIRECT"; if(isInNet(myIpAddress(), "10.0.0.0", "255.0.0.0")) { if(isInNet(host, "10.0.0.0", "255.0.0.0")) return proxyOff; else return proxyOn; } else return proxyOff; }

So with the .pac file, the browser has Internet access. Other programs do not function, and I'm looking for a software recommendation to port all programs that seek web service to pass through the proxy.

I am also looking for a way, if possible, to proxy within a proxy. Meaning that while it is necessary for web browsers to use this .pac file to access the Internet, that another proxy can be set to be able to access Internet sites through an external server. Any ideas?

Thanks.