if the EX8000 is the Korg rack of the DW8000, I have just finished a version of my PC program that connects a DW8k to the BC.
There are, in fact, 2 versions, one of which should allow you to use any layout not just the one I have suggested.
It is a conversion of my DW6000 program at the request of someone on the Yahoo DW8000 group so there is more info there.
This is a link to my DW6k page that has a video about how it is connected up.
At the top of the page is a link to the DW8k page with the two versions of the program.
Is another similar program that connects a TQ5, a 4op Yamaha FM synth, to the BCR2000.
As you can see the PC screen acts as a set of labels for the BCR2000 .
The program keeps the BCR in sync with the synth when it changes patches.
So what you see on the screen is what is happening on the synth
I hope these might give you some ideas about how you might approach programming the BCR for your other synths
All the best
Royce