The following example uses Match.Result to extract a protocol and port number from a URL. For example, "http://www.contoso.com:8080/letters/readme.html" would return “http:8080”.
String Extension(String url) { static Regex r = new Regex("^(?<proto>\\w+)://[^/]+(?<port>: \\d+)?/","c" ,"${proto}${port}"); return r.Match(url).Result; }