Here is the result of my playing around with Subsonic's REST API tonight. This script searches for a song in the Subsonic library, queues it in the jukebox playlist, starts it playing on the server, then stops it and clears the playlist. This requires Subsonic. At present, they include the REST API that this script uses in the 30-day trial, but then it goes away unless you upgrade to Subsonic Premium. Change the variables at the beginning to represent your server URL and user account. (My server happened to be running on the same machine on port 85.) The account must exist in Subsonic and must have permission to play files in jukebox mode (which is not a default permission). Lastly, you probably want to change the parameters in the _SubsonicJukeboxAddSong function call to represent a song that is actually on the server.
I didn't find the right solution from the internet.