Using a USB modem with an ethernet wireless router

Hi there...

I have 1 PC and 1 Laptop both running wndows XP Professional.

I have a USB DSL modem connected to the PC and my laptop is wireless
enabled. Both have ethernet LAN ports.

I have just boght a D-Link Wireless Router (DI-624+) which connect to modems
through an etherent connection only. When I rang D-Link they said that I
would have to enable Internet Connection Sharing (ICS) on my PC with the USB
DSL modem attached, but did not offer any assistance as to how to set it up.

MY PROBLEM: How do I get this configuration to work? Does the wireless
router therefore connect to home PC via its WAN ethernet port (the one that
would USUALLY connect to an etherent DLS modem) or does it connect to the
home PC via one of the 4 LAN ethernet ports? (my guess is that it
connects to through one of its 4 LAN ports)

My wireless laptop has no issues connecting to the router, but how can it
then get access to the shared Internet connection?

I don't want to by a new modem just for this!

please, any help?

thanks!