I have a MBP and do wireless presentations in a small building. The building has a sound system in it consisting of a mixer, an amp, and a speaker system throughout the bldg. I would like to show a DVD that has an included audio portion. Is there some way I can output the sound wirelessly and connect it to the audio system?

I've done a little reading and think something like an Airport Express sounds like it might work but I am not sure. Any suggestions would sure help out! Hope I've given somebody enough info to work from.