Sending the same midi commands from control keyboard to plugin and external instrument

Hi everyone,

I recently added a Leslie 2101 amp to my rig, and I'm trying to set Logic up so that I can use it to amplify the Vintage Organ instrument, bypassing the cabinet simulation. The 2101 has a midi input that can be used to control the Leslie speed, hard-coded to respond to Mod Wheel.

I already have everything working for a pre-recorded midi region; I created a summing stack with:

1) an instrument track containing the Vintage Organ instrument, cabinet turned off

2) an external midi plugin track, sending to the Leslie, with a Modifier midi plugin converting Sustain messages to Mod Wheel (because in previously recorded midi clips I used the sustain pedal to control the Vintage Organ's simulated Leslie speed

3) Input channels to record the microphones directed at the amp

This works great for "reamping" pre-recorded midi clips played against the Vintage Organ instrument with its Leslie simulation.

Now, I'd like to be able to play this same setup in realtime. Everything works fine, except for the fact that I can't get the Leslie to respond to speed changes. I'm not sure exactly why, but I guess that something in the summing track setup doesn't trigger the Modifier, or doesn't pass all messages to both tracks. So in short, what I want is that both instrument tracks (Vintage Organ plugin and External plugin) will record from the same input, while the Modifier midi plugin on the External track processes the events, and then send the processed midi data to the midi out port.

I'm guessing that the Midi Environment window is the answer, but honestly I can't figure out how to make it work and it's not very well documented....

Thanks!

Shai