Personally I would do what Charlie says and then export a single, long audio track. Then import to DAW, split every 12 bars to separate track, duplicate regions to extend amount of bars etc and then export stems as stems. I guess it depends how quick and familiar you are with the DAW.

But that got me thinking, could something like this be done in Realband? I've no idea because I don't use it but if it's possible then that might be the way to go.