Move along arc

I want a sprite to follow an arc. For example, a baseball hit up and into the stands. How do I create a bézier or at least smooth vector curve? I thought to code the baseball like this . . .

when flag clicked
go to [ ballStrikeSprite ]
repeat until [ touching [ upperDeckSprite ] ] 
      point towards [ ballPath ]
      move 3 steps

Will the Animation library help?

Lots of interesting stuff in that library. I am liking your drill-down organization suggestion even more; put everything in one library with easier access. Anyway, I ended up getting myself confused in Trig. Mostly trying to adapt Javascript examples found online, attempting to create natural path for the baseball.

The problem isn't making a ball sprite follow a path. It's making a uniform path. So, perhaps this is a suggestion for Snap! 6: a request for making Bézier curves in sprite Costumes > Paint > Vector.

Moved the thread to that topic.

Edit: Very unlikely for 6.0, which is imminent; the vector paint editor belongs to @bromagosa, who is absurdly busy right now. Maybe 6.1.