i feel this is honestly probably the biggest advantage for hardware synths. you can simply change the banks by pressing a button or turning a knob. i have never been able to figure out how to change patches in VSTis with a controller. seems like something that it should be able to do at a minimum!!! 

anybody figure this out at all?

p.s. i understand it would be impossible in things like dimension pro as it seems you have to actually load a file or something and there are no "left right" buttons in the plugin. but in z3ta, you should be able to do this somehow.

The short answer is that if a soft synth supports Program Change commands, you will generally see Bank and Patch lists in the corresponding widgets of the MIDI track (or MIDI tab of a Simple Instrument track), and the Patch Browser at the bottom.

Z3TA+ does in fact support this. But as you figured out, Dimension Pro, and other synths that have to load big sample libraries don't generally support MIDI Program Change, though I'm sure there are exceptions.

any advice on how to link this to my keyboard?

Here is the problem...a soft synth will take time to load another patch into ram and you do not want that occuring during the middle of playback.

The solution...you have unlimited tracks in Sonar so create another track and load another instance  of Z3ta.

oh yeah, i am not thinking of doing this during project playback, but rather just during the jamming / writing process.

i can do this with z3ta and oxy 49 controller. the best handling ive seen for it is in kontakt and massive.

oh and with z3ta 2 what you can do is create a subdirectory with the patches you want to use and then midi learn the left and right buttons and map them to your keyboard to scroll through them.

the other thing that ive been doing in dimension and rapture is reconfiguring sfz files to work with keyswitches. takes a bit of programming but works for the most part like a program change.

so what you are saying is there is no generic patch control pre-defined in the vsts? i thought vstis were programmed to midi standard, which accept patch control... ?

some are and some arent. comes down to the programmer and needs of the synth. as an example take a si keyboard track and add automation on the midi lane. volume is mapped but pan isnt. general midi synths are mapped to the midi stanard but other synths the mappings are left open to assignment. you can see this in kontakt too because there are so many diff ways to map parameters to controls.