This abstraction requires PD extended - it allows to route an audio signal to different outputs, nothing more. The abs here is a 4 way switch that can easily expanded to more.
The [osc~] is a test signal. The 4 physical [dac~] are there to easily see that it works right on the audio interface but can be easily replaced by different [outlet~] or a different signal processing.
Inside the abs is a radio button that gives an example how the switch is operated by remote. You can replace this by a MIDI or a whoknowswhat controller.
Perhaps a banal thing but it took me quite a moment to figure it out. Also I can't think of anything more elegant. If you have a different solution, please post it as a reply. We're all learning, aren't we