How to set a proxy for private websurfing

I would like to ask the community how to access the web from a chat program which is installed on the computer. Does anyone know how to set things up to make this happen? I have several different proxy addresses i could dynamically change daily. I have tried some but im not knowledgeable and havent been able to make proxy work for me.
Computer runs on Windows 7 Home premium 64 bit and I use Firefox 3.6.4 as my browser.
I would appreciate any suggestion from either knowledgeable persons, or someone that has made it work on their computer.

Thank you kindly

 

Details about my need to set a proxy to surf the web

thank you Mr Andrew Wong for responding;

I did not know what mIRC meant, so i 'googled' it...and yes it sounds like if the ones I want to visit and use are similarly designed as the mIRC ... their addresses from where i have downloaded and installed on to my own computer what they call "Client/Server" so I could then access the program from my computer (hopefully via a proxy) are:

<Addresses removed - suspected spam>

Maybe if you are kind enough to take a peek on those addresses you would understand what it is im faced with.

Thank you kindly for your interest and goodwill in helping me.