Can i have a setup like this?

Ok... well i had asked this in another thread, but the overall question was just taking it too off topic, so i decided to start a new topic.

Right now im in the process of building a new gaming rig, and since my motherboard comes with onboard sound, i figured i'd hold off on the soundcard for now (allows me to save up for something worth buying).

What i'd like to do is have 2 setups somewhat... I was thinking i could get something like this. I would keep the little external excessory on my desk, and use it like anyone normally would (given that the external attatchment has a place for my headsets mic/headphones).

I would also like to have a way to disable it and re-use my front panel audio ports on my case though the onboard sound whenever i take it places (LANs of sorts)...

would this be easy to do? or does it sound too complex?

thanks for any help/advice/whatever anyone has.

The BIOS can easily be used to toggle on/off for onboard sound.