Networking with wireless internet

Hello,

ok heres the problem, i live in a caravan with no phone line access point, so i use a USB wireless internet service, this is plugged into my desktop pc running win xp, i used to use a crossover cable to connect my laptop to my pc and i could access the internet fine but tripping over the cable got irritating so i bought a wireless router.

wireless router is up and running fine laptop connected to the router fine also i can access files on my desktop from laptop, is there a way for the laptop to also access the internet directly from my desktop pc through the wireless router bearing in mind i have a USB wireless internet service?