The mediaplayer MPC-BE has web-based controls (MPC-HC should be similar, but I have not tested with that one).
I've created virtual inputs and outputs for controlling the media player from Loxone.
- The outputs send virtually all commands that are supported by the web-api (these commands are visible in the settings page of MPC-BE, and on the sample page http://<your ip>:13579 ). This is quite a lot, I use just a subset in a mediacontroller block, but figured I might as well put all of them.
Not all are tested, there may be small typos or so.
- The input take all values that are possible (by default these are on the page http://<your ip>:13579/variables.html ), except for the filename as Loxone cannot read them easily. The update for the refresh is set at 10s (the minimum, so the update of the playback time for example is every 10 seconds.

Hope this helps someone.
Jörg
PS: Feel free to put the files in the wiki / faq.