According to the EL900 owner's manual, its Virtual Acoustic voices cannot be edited, and after-touch for these is Control Change 16 (XG Assignable Controller 1).
Hardware:? As well as those? in my previous message on this subject, Yamaha-supported PLG150VL hosts include S90, Motif ES and MU2000. A friend had a Kenton Plugstation to house 1 to 4 PLG cards including PLG150VL - I don't know if these are still on the market..
Software: If I recall correctly, the PLGs are shipped with an editor plug-in for Yamaha's XG-Works sequencer,? If you want a more powerful (and more pricey) editor, look at Rudy Verpaele's? (http://vl70m-editor.com/site/ ?)? You may use one of the other editors in the Files section, but they are supplied as-is with no guarantees.
If all you want is to change XG midifiles to VL-XG, see Mid2VL.java in "VL Control Surface.zip" (this may need changes for PSR panel voices, Bank Select MSB 0 LSB 112-126)?
