Setting up a BUS for MIDI?

[Elton Hyland]

Greetings, can't find an answer in my searches so here goes. I have a Roland XP-80 setup with a Command 8 and 003 Rack. Using PT LE 7.3. I can record MIDI just fine using an AUX track but I guess I'm not understanding setting up a BUS. I can set up a BUS on an audio track but cannot find out how to do this with a MIDI track. My goal being able to use plug-ins such as reverb etc to tweek the MIDI track. I'm using the Roland XP-80 patches for sound and not an installed plug-in. Is this even possible? What am I missing? Thanks