Domain

Hello everyone,
i am arun, i am new to this form and the job i am doing,,
now actually i need help is accesing my domain name,
here is the scenario
when i type my arun.home.com, domain name it should point to my computer,
actually now its pointing to my router. when i type this in my address bar in browser it opens my cisco firewall. now i need to know how to point the domain name to my computer instead of router, can any one heklp me
plz mail me arunprasathmsc@hotmail.com
thanks in advance
arun