You need to set up a second hardware profile on the box. This is the only way to have two sets of network settings on the same physical card - SHORT OF actually binding two different IP addresses to the same card. Trust me, you don't want to do that.
This is a terrible idea! Even if it works (no intervening switch to drop packets, unlikely on a corporate net) it's a horrible violation of good network administration.
Like bollocks it is. And in usual hit'n'run fashion, there's no exposition of why my perfectly working solution to Christian's problem is "terrible".
You're getting very good at spouting impressive-sounding but fundamentally broken advice, Ross.