Is there an audio mixer I can use with skype....?

Here's the deal. I have a digital studio setup using a slide mixer and inputting through an Mbox into a Mac G4. Normally I use this to feed Pro Tools for production and editing. What I want to do now is connect the Mbox to my MacBook and feed directly to Skype for an on-line radio show, so that I can do live mixing and level adjusting during the broadcast. However, I'm not sure how I can ign it to feed Skype from the Mbox. Is there anything special I'm going to need to do? I can fun firewire from the Mbox to the MacBook, but I'm not sure if I'm going to need special interface software to recognize the Mbox as the input device for Skype as opposed to a headset plugged through the normal earbud plug ins