[flommer]

You can still use the sounds on the keyboard.. Just have ProTools send the MIDI out to it. You probably will need to turn "local Control" off on the keyboard. This kind of separates the actual keys from the sound module as if you had a controller and a rack synth ( that's my little MIDI setup). So you play the keys, record the midi in protools and send the midi out at the same time to the synth so you can hear it.. You can also install the patch names in Audio MIDI setup so you can change patches from protools.

Then of course you need to have the audio from the synth come back in to protools to hear it with the mix... You can do that with an Inst track or with an Aux input. That way you are not using up an audio track in ProTools..