Custom model spawn icon? (materials/spawnicons)?

I have made a custom tool that uses the “propselect” control in build cpanel. Thus it uses the spawn icons in Materials/spawnicons/models. I want mine to be a custom image png. Problem is, th only way to do it is to let the game generate one, then go into the folder and replace it with my image. It works like that, but I cant put a materials/spawnicons/models/ directory in my addon and have it work that way, it just goes back to the generated image. Is there a way I can pack a custom spawn icon with my addon to make it work?