so you what you want is:
If some type's www.sommtinh.com it wil go to your computer?
If so goto www.no-ip.org and download the client and install
it(instruction are on the site)
open you apache config file and look for:
ServerName 127.0.0.1:80 and chage it to:
ServerName somting.no-ip.org:80(chage the somting with your no-ip
achount)
restart apache and your set.