I note that I've done most of my actual file and audio processing under either macOS or Linux, where I'm much more familiar with the scripting tools. I might not be able to help you as much I'd like.
I'd suggest taking a look at my voicepack template or at least Kregano's tutorial that it's based off.
Why? Well, Kregano's tutorial covers using a script (by robojumper) that fixes several problems with the built-in approach to voice 'banks', and my template then tries to help you avoid having to decide what to name bits of code and stuff.
If you do try my template, I suggest calling your project and your mod something like 'SlickSlothGrenadierVoice' or something (without spaces, and the same name for the project and mod) otherwise it ends up even more confusing in places...