You're probably going to have to log onto the router to change some settings around. Go onto your brother's computer, type in 192.168.0.1. (or whatever the Belkin's router IP address is) and dig around.
Not to be harsh, but you just spent around $2k on a laptop. You should be able to figure out how to get your computer to connect to your router. It will connect perfectly fine with Apple routers, and I use a CompUSA 802.1g router I've had for years and never had an issue.
FWIW, the only time I couldn't connect to a router was when I used to set OSX 10.4 (Jaguar) to a set IP address. Had to set it to auto everything to get it to connect.