From what I can see with Optimum Birth, they're set up so that you just buy each module as you're ready to do it (each one is $110 and there are 4 modules that make up the complete course) and download it yourself onto your PC. They have a page set up on their website where you buy the modules, so I'm thinking I would just buy that one module. Obviously you wouldn't get any formal recognition for it because you're not completing their full course, but that wouldn't matter since you've completed the CBI course. It would just be to have the "local knowledge" kwim?
So that's kind of my plan at the moment.
Good luck with the seminar, sounds like a great idea!