Sonar X3 Producer + Edirol PCR800 + Arturia (or any other synths...)

Hi Mats,
 
It could be done only if the navigation buttons on the synth are MIDI assignable.  If those controls are not exposed to MIDI, then hopefully the soft synth's has some sort of control configuration capability.  Nonetheless, if those controls are exposed then MIDI learn is the easiest way to assign soft controls to hard controllers.  You can try to using SONAR's ACT which is a hit or miss or you can try to use the PCR's Editor app, which in pretty easy to use and relatively easy to save configurations.  In both methods, again, the synth control must be exposed to MIDI.  That can be easily determined by opening SONAR's MIDI Event View.  Just press record, change presets, stop record and then check the Event View.  If those changes are reflected in the EV, then you will see the MIDI control number/note that you can then assign to a control button/knob/slider in the PCR's Editor.
 
If you need detailed steps for the above mehtods, hit back.   These instructions can easily be found in SONAR's help for MIDI learn and ACT and PCR's help for Editor.
 
Kind regards,
 
Living Room Rocker