You need to use the Nova II in it's Performance mode. Programs can then be assigned to any of the 6 parts of a Performance. Download the help pdf "a guide to using the Supernova II Multitimbrally with a sequencer" above for full detailed instructions. (Any references within this help pdf to 8 parts should be read as 6 parts for the Nova II)

http://www.novationmusic.com/support.asp?supportid=16&view=TandT