KawaiK3Zone

I have a K3 and am using it via a USB MIDI interface wtih a Mac with
GarageBand.  
While using it as a controller to play the software instruments on
the computer (like 
grand piano), it plays the highest notes on the piano, but since it
is not 88 keys, 
doesn't play any of the lower notes found on a piano.  I rarely would
play the top two 
octaves on a piano, but I would play the bottom two octaves now and
then.

Any idea how to make it play the lower notes on the software
instruments?  (Is there a 
way to drop down an octave or two in the MIDI controls, similar to
the Preference-
>Range feature on the synth?)

Thanks for your help.

-Chris