Before I get to my question, I want to explain what I am hoping to be able to do.

Currently I am taking high quality recorded lead vocals from past recordings (with all other instruments & effects muted) and finding/collecting sections where I held notes that I sang in regular non-false etto, capturing the various A, E, I, O, U sounds. So 5 in total. Once I have them all and extend them to around 10 seconds via editing (or possibly loop them depending on how smooth/or not the loop points are), and adjust volume levels, etc., then I'll save them as .wav files and import them into a PART as 5 separate elements, separating them by velocity ranges. I realize I could use the voice choir sounds that are Preset waveforms in the Montage; however they are more softer/choir sounding. I am looking to have rock/pop voices with a bit more raunch to them.

What I'd like to then do is record the MIDI of these new PARTs in Pro Tools for a particular song where there are vocal harmonies. I'll edit the velocities to the proper A, E, I, O, U element of that PART based on what the words are in that song, then save that MIDI as a file (along with other instruments recorded/sequenced for the song). Once I import the MIDI file into the Performance as a Song (or in my case I will save it as an Audition so that I can just hit the Audition button to start the song), I would like to have the 'Vocal Harmony' PART also triggered by Vocoder while I sing, so that the key presses of the notes/keys are played via MIDI and the sound is triggered by a mic through the AD Input with the PART set to Vocoder...!

Is this even possible to have that particular PART's notes played via MIDI/Song (instead of having to manually play the keys on the keyboard) and trigger the sound via Vocoder? Or does the vocoder functionality only work if the PART is under KBD CTRL and the keys are physically played manually/live..!?

In essence, I'd like to have my hands freed up to play other sounds on the keyboard, while having harmonies sound/play from real pre-recorded vocal sounds in a PART trigger by the vocoder, while I sing the main lead vocal! (fyi ... I plan to have 2 Mics. A headset mic just to trigger the Vocoder sounds on the Montage, and a separate main vocal mic on a stand plugged into the PA Board...)