Or you could make things even easier and download multiproxy, make sure that a proxy list is imported then go under options in mirc and goto localhost and under on connect alway get ip address, then choose a proxy from the list under multi proxy and type it in the localhost bar, make sure to leave the ip address blank, then go under firewall and choose proxy then choose dcc then enter a address with the proper port defined, and leave everything else blank. and then connect to a server, its that easy, sounds like a lot but it is not, takes all of 5 seconds after intitial setup. hope this helped take it easy. BTW though like so many have already said "security through obscurity" is not real security.
A nice IRC program to use is BlackDevilScript.
I Like it because if you get banned u can press one
button and u can get into the chat again.
i agree wtih instronics, turn off your dcc and make sure you don't have anything that could keep you vulnerable. decent software firewall should be sufficent. check out cisecurity.org/com, they have nice little templates for you to harden your machine as well.