IPWorks Does support Squid proxies. Squid is an HTTP Proxy, meaning that it accepts HTTP GET requests. It does not accept HTTPS GET requests. However, Squid does support HTTP Tunneling for non-SSL and SSL requests. So, here is how you need to access it:

https1.FirewallType = nsoftware.IPWorksSSL.HttpsFirewallTypes.fwTunnel;
https1.FirewallHost = "62.2.204.30";
https1.FirewallPort = 8080;
https1.Get("https://www.microsoft.com");

If you were getting a non SSL URL, you could use the same HTTP Tunneling code above (except with an http:// url) or you could use:

https1.ProxyServer = "62.2.204.30";
https1.ProxyPort = 8080;
https1.Get("http://www.microsoft.com");