Mixbus BiabVstFX Band-in-a-Box DAW VST FX Plugin.dll worked.
Mixbus 4 didn't see the Band-in-a-Box DAW VST Plugin.dll instrument
so I used PluginFlipFlopSynth.dll then loaded Band-in-a-Box DAW VST Plugin.dll instrument into it, this way you can send midi from the Biab plugin to the DAW then send the midi channels to different tracks with different Virtual Instruments.

Attached Files (Click to download or enlarge) (Only available when you are logged in)
MixBus-BiabVst.png (212.18 KB, 27 downloads)
MixBus-BiabVsti-PluginFlipFlop.png (442.14 KB, 27 downloads)