Animating an arc in AS3

i need to animate a sprite in an arc motion using dynamic start and end positions at runtime. hopefully with an easing function at the end of the path. since i’m not animating in a straight line i don’t think i can use Tween since that class doesn’t seem to support anything but a straight path. nothing’s in the timeline. actionscript only.

any advice as to the best way to do this? is the Animator class using XML the best way? can i use the BezierSegment class? can i create a custom easing function for Tween and get an arc path that way?

the tough thing about using an XML doc is that i have to calculate each keyframe at runtime since i don’t know the start/end points at compile time. that’s an option but i’m wondering if there’s a simpler way.

any advice appreciated.