Okay, I have a projector that spits out doents with a specific extension
(let's say ".abc").

Does anyone know how I can "register" the extension ".abc" so that all files
with that extension...

1) have a specific icon that's bundled with the projector
2) launch the projector when double clicked (and set a variable somewhere
that I can check to see what the path for the file is once the projector

I got this working on Windows 2000 so far, but I don't even know where to
begin with OSX.