Thanks for the update - sorry for contributing to its need! Look forward to some serious ZenEdting now.
You do still need a sound source of course. Drum Tutor to the best of my knowledge does not produce any sound. The typical usage of it is to have a Roland sound module (such as the HD-1) plugged into it. Do you own a sound module that has both MIDI IN as well as OUT? If so, the easiest route is probably to plug your zen into the module first, and then plug the module in to the PC.Of course, that makes sense. I was trying to avoid the module, but clearly it would be too fiddly to use BFD. So, to use my TD-20 module, I'd have to Zen MIDI OUT to TD-20 MIDI IN; TD-20 MIDI OUT to USB and USB MIDI IN to ZEN MIDI IN?
Alternatively you could use a VST based source (such as your BFD Eco). You might need to fiddle around with port sharing then though. Depends on if either piece of software takes exclusive use of the MIDI port.