Most schools will have port 9999 blocked. In fact, typically, schools and business organizations will usually use a firewall (an electronic device which filters, occassionally tracks, and attempts to prevent unauthorized usage of an internet connection to increase security) to block out every port except for the "standard" ones. Standard ones would be like 80 (http), 443 (https), 25 (mail out), 110 (pop3 mail in), 21, etc etc etc.

There are usually ways around these, but given they are blocked for a reason, I would not suggest doing this. Rather, you can consider getting your own dialup connection in your dorm (if your phone systems allow dial up, IE, analog only), via a Vonage system ($15 bucks a month, but make sure its ports aren't blocked) or maybe some generous soul will finally get around to making a proxied java/Flash based one. For now however, those don't exist. Typically people get around them using their home machine as a proxy, but, again, this probably is against the rules of your school and compared to just telnetting is a relatively more complex procedure to set up.