Bicycle Mechanics - Brake screw... casing.... thing

So I've got a track bike and I'm trying to put a front brake on it, and I happened to have an old ultegra 500 front brake lying around and decided I would just use that, however, the little tube thing that screws into the opposite side of the fork(picture 1) doesn't come on the frame I bought and I can't find the original one, I've got one for the rear brake on another frame of mine(picture 2, I pulled it out all the way so it's sticking out, but you get the idea) but it doesn't really seem to want to come out. Basically, I want to know what this thing is called and whether or not I can get one at the LBS. Thanks

P.S. Sorry about the quality of the pics, my camera phone is pretty fail.

Recessed nut, recessed allen head nut, recessed allen..among a few.
They are available in different lengths.
Here's a few examples:
http://www.loosescrews.com/index.cgi?c=Brake&sc=Recessed%20Nuts&id=66567477436
You're LBS should have a few hundred laying around.

Get a bolt or a something that will fit into the brake bridge from the other side of the recessed nut. Make sure that whatever you use is large enough not to go into the recessed nut and mess up the threads. Tap lightly with a hammer. It should come out.

Excellent, you're amazing, should I just bring my fork in to get the right size or is it 1" for a... "Mercier Custom Drawn Butted and Tapered 4130 Cromoly 1 inch steerer with custom brazed flat crown"

Get a bolt or a something that will fit into the brake bridge from the other side of the recessed nut. Make sure that whatever you use is large enough not to go into the recessed nut and mess up the threads. Tap lightly with a hammer. It should come out.

Brilliant, with a larger allen wrench and a few love taps the other one came right out. Thanks guys, and now I know what it's called for future reference on top of it all