I think you would handle this by storing them in an array, and selecting them from an array. I don't know off the top of my head how you would code this, but I hope this can lead you in the right direction, and offer some prompt help. I think this may help: http://accad.osu.edu/~aprice/courses/694/variables.html#array
Seems like a Shelf button would be the best way ;) Whargoul's idea is a solid improvement though, a more generic scriptJob that queries a specific custom attribute is much more flexible than a hard-coded one, and allows multiple of these "master control" objects to be used without writing more than one script. You could…