All I've tried is going to Options->Preferences->Control Surfaces ->Add.
The CS-10/2 does not show up on the drop down list.
That would have been too good (and easy!) to be true!
I guess I'm wondering if there's a way for Reaper to "Learn" a control device by "recording" the MIDI commands and sysex that get sent by the CS-10/2, and assigning them to Reaper commands.
As an alternative, is there a way for me to program scripts that would recognize a midi command or sysex string and then manually map them to Reaper commands?
Keep in mind that just EXPLAINING that last one was stretching my technical know-how!
Thanks so much to everyone who's helping me figure this out!