Patches and discussion for Ensoniq VFX family

For many years I have been trying to figure out how to control a 
yamaha dx7 from vfx. I can get the sounds in preset and seqencer 
mode but can't copntrol the performance(mode) volume, release etc. 
from vfx. Their was a letter in transoniq hacker that says this is 
possible but did not give detailed settings of how. I've tryed every 
combination of buttons but nothing works. Ever year or so I ask this 
question and nobody answers. Someone out their has to be controling 
another synth with their vfx, please help.