Texture masked glow post effect

Some time ago, I worked as an artist on a non-unity game where we had this cool post glow effect that was controlled by a single channel on most of our object's texture maps. A "glow map" if you will. This was a space game and it looked really good to have all the little tiny lights on a space ship or station actually appear to have volume rather than just doing a simple self illumination.

I'd like to implement an image effect/post effect similar to this, but I'm not sure where to start. I took a look at the source for the existing glow effect, which sort of glows the whole scene. So, I'm guessing I would have to render the scene out with replacement shaders(with my glow maps) as a render texture, blur that, and then compose it additively on top of my normal render. Am I on the right track? Is there an easier way?