I have been waiting for the MVocoder from Melda to go onsale and just installed it.  While the tutorial videos look very helpful, the intro video says "the modulator is received through MVocoder's side chain input, which I need to activate".  He then clicks on a box that I do not see in Sonar!  After spending time looking online and through the documentation, I am at a loss. 
 
Anybody go through the setup process with MVocoder?
Thanks!

The button in the video is not part of MVocoder. It is part of the the DAW's VST header. There is no button on the VST header in SONAR to turn on a plug-in's side chain. If the plug-in has a side chain input like MVocoder, it is always available in SONAR. After inserting a plug-in in the FX bin, the side chain will show up in the output and send drop downs of all the other audio/instrument tracks and buses.

To spell it out a bit more ...
 
Track 1 - Modulator
e.g.,
- Audio Recording(or realtime) e.g, voice (microphone)
- MVocoder in it's FX bin
- Output of Track1 to Bus/Master
(I'll typically pass it to a bus with a limiter to avoid peaks, enroute to master, but MVocoder does have an inbuilt limiter (when activated)).
 
Track 2 - Carrier
e.g.,
- MIDI Instrument
- Output (or Send) of Track2 directed to MVocoder's sidechain input

Note:
1. You'll have to experiment to find a good comibnation (common spectrum) of Carrier 'instrument' and MVocoder Preset(/created). MVocoder Graphs can assist here. (Just start by trying a Preset like Reverse Milkmaid and a Powerchord guitar / Sawtooth type instrument)
2. You'll have to alter the midi notes to get the intonation of speech. (Just start with a straight note)

Okay, thanks guys.  Shellstax, I followed your instructions and it does indeed show up as an output option for the Midi track when used in the FX bin of the vocal. 
 
Unfortunately, it doesn't seem to be modulating -- it is just filtering the vocal.  That is my ignorance -- this is not a simple tool, I guess.  Now i'll go back and watch the videos and hopefully take it from here.
Thanks again.

Persevere, cwestmont. It took some tweaking but MVocoder is now my go-to vocoder plugin.
It really helps to understand vocoder basics, though. I reviewed this video several times, pausing and making notes as I went.

Okay, this is how it is working for me currently with Dimension Pro as the synth of interest (as modified from suggestion above):
Track 1 - Modulator
- Audio Recording(or realtime) e.g, voice (microphone)
- MVocoder NOT in its FX bin
- Output of Track1 to MVocoder input of Track 2
 
Tracks 2 & 3 - Carrier
I inserted Dim Pro as instrument with standard 2 track config -- e.g., Track 2 is audio and track 3 is MIDI
Insert MVocoder into Track 2's FX bin and it should show up as an output option for Track 1
Track 2 output points to Master bus
Track 3 is Dim Pro Synth, with output pointing to its usual audio companion (Track 2 in this case)


Then I can pick different Dim Pro patches to experiment with how they fit with the modulator.  This gets the vocoder effect i wanted. 

Fair enough - many ways to skin a cat ... and according to requirements.
 
But I find the carrier (Dim Pro in your case) more 'simply' added (dragged) as a 'Simple Instrument Track'.
The single 'Simple Instrument Track' is effectively your Track 2/3 midi/audio/routing merged into one.
 
You can still easily try out the Dim Pro progs from the Synth Properties interface -just double-clicking in the DimPro/Rapture program Browser.
:)

thank you everybody for these tips w/setting up MVocoder.  it's definitely a million times more complicated than Image-Line's Vocodex! having twenty thousand or so choices of Carrier is pretty overwhelming, but i went with Native Instruments' Monark as a place to rest for that because it's a great simulation of a Moog synth.  a weird thing, though, is that once i got into the deeper functions of MVocoder, oftentimes when i would alter parameters, i could not hear anything different happening.

Vocodex is about $66 in the cart at JrrShop and AudioDeluxe

Is there one in their free bundle?