Actually that’s why I created this preset with Logic’s Modulator Midi-FX. I’ve assigned it to the Pitchbend parameter because its a universal control/parameter that all instruments use.
The LFO is for subtle variations in pitch, the Envelope is just for the attack portion. The harder you hit a note the more likely it will bend sharp just a little before stabilising. Playing studs more quietly can often bend up in pitch too, especially if it’s a blown instrument.
Of course this only helps you if you have Logic, but perhaps your DAW does have some kind of similar midi effects thing going on??
In terms of Ovox, I’m not confident you’re going to get the best results because it was designed to be a synthesiser over other things. I’n fact, I think the only way you can change the pitch is denoting how strongly you want the source/voice to be corrected. The pitch controls themselves are tied to the synth engine it would seem.
However, Vocal Bender might work better in this situation if you have it. First try a little random modulation to affect the pitch in Cents. Once mastering that you could try add an envelope to affect it as well, just as I did with Modulator. Maybe try extreme settings at first so you know that it is in fact working, then dial back the strength until its only doing +/- 5 cents or thereabouts.