Implementing morph targets

I’d like to create some facial morphs for greater character customization, but before I get carried away, is there any way to implement them? For example, would I be be able to mod the character creation menu and add new sliders, or create an in game UI to do the same?

You can entirely change the models the game uses and can update the US the game uses. I don’t know what is involved for the facial morphing but really the only thing restricted at this point is C++ coding.