The TD can certainly play a random audio file when some event occurs. It's a simple feature to set up.
You must have all of the audio files added to the sound library. With 20 or more, I'd suggest pressing the "Import Sounds" button, which will allow you to select a folder and import all of the audio files in that folder.
Once they're in the library, edit the event you wish to play a random audio file. For each audio file, you'll need to press the "Add Action" button, select "Play sound", and select on of the audio files. Eventually you'll have 20 (however many it is, I'll use 20) Actions on the Event, each that plays a different audio file. Finally, press the Action Settings button. In the Sounds section, select the appropriate settings. I believe that when when an Event has more than one Action that plays an audio file, the default setting is to play one of them at random.
I have tried various other stand alone programs but when directing to the audio path it will not accept an *.exe path.* Obviously Tournament Director wants an mp3 or wav file.
Since files ending in .exe are executable programs, it's understandable that a program expecting to play an audio file wouldn't accept that. It's not an audio file. And the TD won't "play" it either. However, the TD
can actually launch another application as an Event Action. Just select "Run program" on the Event Action dialog and select the appropriate .exe file.