Vertext Groups for particle issues...

I’m trying to recreate the new acura commercial with the bullet going through the bottle and the back of the bottle explodes. I have everything made, the bullet, bottle and all the textures / shaders are set. I just need someone to point me in the direction of a good tutorial which explains blenders particle use and explode modifier. I tried the manual but I cant get the particles to come out of a vertex group, they always come out of the whole bottle. I have particular as well which I’ll use to add finishing touches when I bring it into aftereffects but I want the blender explode modifier to make the shatter look real. Thanks in advance.

This is the commercial if you haven’t seen it. http://www.youtube.com/watch?v=josjHiJcCYA