I found this
http://sourceforge.net/projects/delphiasiovst/ so you delphi programmers might be able to incorporate the bbw.exe into a vst as is done something like in realband that calls on c:\realband\data\bbw2.exe (initializing accompaniment)
you could set up a main instance of the plugin on track 1. and set it to track 1. in the vst, with track 2. set to track 2. in the vst and so on or allow the next track as a midi track for the midi notation of that real track.
so the plugin will follow the host synchronization n bpm TPOPSTRINGDIALOG
the vst would need to show the chord window TSSWINDOW and other necessary windows that could be in tab form, might be easiest to follow if you have the chord window like real band continuous unfolded - but basically you just need it for generating up the tracks then move to the daw functions for any further editing.
you should be able to select any bars then click the generate track No.X button on the main plugin window to render a new piece if you don't like the section, without having to generate the entire track.
so the generate buttons would need a drop down menu with real track - drums - user track - super midi and so on with recent generation to choose from could be something like the drop down generate in real band.
you would still need the open save as to import and save an sgu
you can set a bar offset in your daw to allow for 2 bar count off and pickup intro notes.
That is just a startup idea any other users with suggestion, improvements and ides for the vst please post! *
There is a cross platform c++ VSTGUI to create for Macintosh also but by the responses you guys weren't too worried about them.
http://sourceforge.net/projects/vstgui/?source=recommended* again please note "They could keep the existing band in a box how it is 32 for the older users that have been accustomed to it's interface for the last 20 years"