So, dear friends, thanks to all of you FINALLY I'VE GOT IT!
The way I' ve chosen is:
1. In Logic I create a 4 voices track (channel 1.3.4.5.) and set it to MIDI Channel: ALL.
2. In VE Pro I insert 4 organs each one corrisponding to a channel (1.3.4.5.)
3. I control the orizzontal movements into the Matrice via Velocity. The vertical movement into the Matrice are done via 4 "tracks" (or Event Definitions, in Logic language) in Hyper Editor set as "Control", each one on the corrispondent channel (1.3.4.5).
4. The Slot XFade is controlled in a similar way via 4 "tracks" in Hyper Editor. This is very usefull to change register during a long note or chord, for very powerfull effects.
Everything works perfecttly! I really wish to thank all of you for the great help.
All the best to you
Roberto