Sub folder in media library – possible?

Is it possible to add a sub-folder to the media library? I ask because we use a click-to-call interface on our site. The UI for the function requires three images, to be named very specifically, that make up the graphic that displays (voice_reponline, voice_repoffline, voice_repoccupied). In the click to call platform I have to provide a URL where the images are saved so it pulls the right images.

However, I’d like to create separate image series to go on various pages of the site, each with a different call to action; “speak to…”, “call us now”, “click here to be connected.”

However, b/c the file names have to have specific titles in order for the click to call platform to recognize and pull the right images, I can only seem to add one image series to the media library.

Any advice on adding a sub-folder to the media library, or another area where I can save graphics is greatly appreciated!!