ok, is there any way you could trick the defs toolwindow into showing what you want. If you right click in the defs window and select "others" there's a few mysterious things there.
Is running a search off a single keystroke and using search results not good enough?
I might be able to sketch up some slick C code for a toolwindow in the next couple of weeks that you can play with, if you can suggest how it would work. It might be possible to change the defs toolwindow source code to show them too.