I'm new to the Audya, so there are probably other ways of doing this. But I make my own programs to go with my regs.
Press programbutton and second voice button on- go to the sound you want, press edit- in the page that shows, press- second voice 1 -(user 2/7) here you can select the sound- effect- volume, etc. for the second voice F10=controls= portamento, aftertouch,expression, etc. when done, save it with a new name or as it is.

[This message has been edited by skude (edited 09-22-2009).]