Remotely connect to router

i have a wireless router connected to my adsl modem. each computer within the home network has its own dynamic ip, assigned by the router, including my ibook. i am trying to access my modem and or my laptop from uni, how can i do it??

i tried typing in the modem’s wan ip, but it does not seem to connect to it. then i try typing in my ibook’s ip with @modem’s ip in the url but that doesnt work… can anybody help??