My ISP has setup a Steam content server so that you don't have to waste bandwidth downloading games, however some bandwidth is still used unless you setup your firewall correctly. They have a guide on their website but that's for Windows7/Vista's default firewall. After a bit of research I concluded that Windows XP's default firewall didn't have this function so I downloaded Comodo's free firewall but I don't understand how to set up the port/IP settings on it. So I come here, in hopes to find help!

Link to their guide (contains IP's)
Screenshots of Comodo rule-setting windows, (Destination and Source windows are the same): 
 



EDIT: Can't seem to fix these hyperlinks, they link to the guide posted on the website of my ISP, well the ones before the pictures