2015-05-28 by jan@...
TL;DR: There is none. The only way is to send a complete patch via Sysex.
I could not believe it myself but the commands to program a matrix modulation path are not implemented on the Matrix-6. This is the one thing they really improved in the Matrix-1000 - which is a slightly reduced and modernized Matrix-6R - as you can send a single matrix modulation path via
$F0 $10 $06 $0B nn ss vv dd $F7
with nn being the path (0-9), ss the source (0-20), dd the destination (0-31), and vv the amount (-63 to 63).
But, as stated above, this does not work with Matrix-6 and Matrix-6R.
