Wired and Wireless – How to Force Internet over Wireless

Hello,
On my laptop, I have a wireless card and a regular wired NIC. The wired NIC is connected to the corporate LAN and the wireless is connected to a Linksys router that is connected to DSL. How can I force any interent traffic over the wireless and any intranet over the wired? The corporate LAN does have a proxy server for public internet.

Thanks.