Kenworth,
Since you are using Cakewalk, I think that you have to get the "instrument definition file" for the casio. Once installed, the list of voices in Cakewalk will match the list of voices in the Casio so you just choose what you need.

Go here, these guys know a lot about Casios, so is Squeak_D in this forum
http://www.originalz.com/casio/casio_bbs/

Theodore