I need to know how to set VST parameters such as the diapason (reference frequency; A at 440hz), midi key mapping and microtonal divisions of the octave through use of Sysex messages. Some VSTs come with microtonal capabilities by including such files as Scala (.scl) files, Keyboard Mapping (.kbm) files or Tuning (.tun) files or others. But I'd like to tell the VST myself what structure to follow with my own system.

Is this possible? Can someone please explain how "micro" tuning is done through midi?

Edit: Any general information on how to do Sysex tunings would be of help. Where does one learn to do Sysex?