Hey,
Please try and c if it is possible 2 program via Continuous controllers (CC messages), I'm not that versatile with Sysex... althoug if the synth sends these messages U cal always program from the front pannel/ knobs, record 2 a midi track in SX (repeat till u get what u want) and then press play!
I know some of the Old Matrix had dedicated knob boxes/ editors so I would b willing 2 bet that they'll be a bi*h 2 program! :(
Z