Difference tween gone curvy?

Alright, so with a basic difference tween, we can animate one value to another.


this.onEnterFrame = function (){
     difX = (targetX - myObject._x)
     myObject._x += difX / speed
}

How would one curve it to that position? I want the starting and ending points to be the same, but with some fun curving in the middle.