It turns out that building meta-ethics from the ground up is somewhat difficult. So I'm going to take a step back, and explicitly describe some fundamental ideas about what morality is. Hopefully this will help point in the right direction to look.
Morality is about answering the question, "What should we do?"
This implies that morality is about willful actions. Morality doesn't apply to things that can't act, and can't make choices.
But morality isn't just about how to achieve your goals. It has more to do with what your goals should be.
Who is left unspecified. Usually, that's interpreted to mean that the answer should be universal, that it should apply to everyone in the same way. I'm not so sure about that. Maybe it just means the question needs more detail to have an answer.
However, morality does seem to be concerned with controlling others' actions. It's frequently used to justify doing something "bad" to someone else if they did something "bad" to you. But then again maybe that's a misapplication...
So, that's not a lot, but it's something. Maybe it will be helpful.