Hi Brian,
You can't send audio through a MIDI port (but the KN USB port can route both to a PC). You will have to hook your Digitech up to the line in on the KN7000 (or both of them to a mixer) in order to route it to your PC.
If you can hear the audio from the Digitech on your KN speakers then you can send it to the PC.
Cheers,
s.