Does the Belkin has Client Bridge Mode?

If the Belkin has Bridge Client mode.

The two devices has to be on the same subnet.

Both should be on the same channel and same SSID.

The Wireless MAC address of the primary Router has to be type into the Belkin otherwise it does not know that it is suppose to connect to it.

Start first with the Wireless Security Off on both Routers, and switch it On only after it works.

I do not about the Belkin, but most old Wireless can do only WEP in Bridge Mode even if otherwise they are WPA capable.