I noticed that the 'Picture 24' library object has a string parameter input which also provides a nice list of all the images loaded into the user's library. According to this forum post, the parameter gs_picture_name has its values populated through the following application query:
There's another query that filters for IES files too. It would be great if this extension could offer methods of filtering for other file types, especially objects, by name, folder, or subtype. This would make it possible to set a range of values on a string parameter, with which you could then call a macro. The motivation for me, is that I'm finding Custom Comp Collections to be too limiting (and sporadically unreliable) - since the auto-generated code for calling the macros won't transfer or return any parameters, the called macro objects end up being entirely static. Our office can get by with just manually copy-pasting the object name, but it would be much better to be able to just move an object into a folder, or save it under a sub-type, and immediately have it populate a values list.