The script job could look at an attribute of the model you select to determine what it needs to select. You'd add a custom string attribute to your "selector" model, and encode the names of all the object you want it to select instead. The script job queries the selected object to see if it has that attrib, if so, gets the…
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…