I read somewhere the the Tyros and therefore Genos keyboards can accept soundfonts (.sf2 format). Take the wave's you want, use a sample editor (there are a few, but my favorite is the Halion series) and export to a .sf2 soundfont.
Now load that into the Tyros/Genos and it should play across the keyboard (as you mapped it) fine.
I have a ton of .sf2's for sale at
www.supersynths.com that will work with Tyros and possibly the Genos keyboards. I am a Tyros 5 owner myself (just got it) and as soon as I get the expansion board (looking to get the 2gb version), I will test my .sf2 samples out on my T5.
Mike