There's no way to get SegaCD games to run on a Genesis emulator that doesn't have special support for the SegaCD's extra hardware (CPU, RAM, Video Scaler chip, etc).
Being that we don't have a Genesis emulator that runs perfectly (full speed, no frameskipping, etc) on the Dreamcast, I wouldn't count on having a SegaCD emulator any time soon. That, and most people seem to have moved on from making emulators for the Dreamcast at this point, sadly.
That said, this was quite the necrobump that was done on this thread prior to my post...