Dave

Have you tried loading up Kontakt / Kontakt Player in standalone mode and using a virtual midi cable to link them. After that, it's just a question of assigning bass to channel 2, piano to 3 etc and, if memory serves, soloist to 7 and melody to 4 (but I might be mistaken with that as I'm not at my music PC just now. The Virtual Midi route is much more stable than using Kontakt as a VSTi.

Best wishes

Brian