Programatically create objects in library which can be imported to stage

Question

I need to create an object in code which can then be imported to the stage. 
Specifically it's a circle with an ellipse cut out of it.  The size and position of the ellipse masked out need to be parameterized by sliders, and the size of the circle as a whole is also a parameter which might be dragged out on the stage.
Does anyone have an example of how to programatically create an object in action script which can be imported to the library which can take parameters (or rather expose some methods) which can be wired to other things in the project like a knob or slider?
Thanks in advance!
Michael Grant

Answer 1

you can use the function below.  call it passing parameters for the circle's absolute x, y, radius and color and passing the ellipses (relative to the circle) x,y,radius x, radius y.  a sprite is returned with the graphics, i think, you want:
////////////  sample function call: ///////////////////////////////////////////////
var c:Sprite = circleMinusEllipse(100,200,50,0xaa0000,-40,-20,40,20);
addChild(c);
//////////// nothing below needs to be changed ////////////////////////
function circleMinusEllipse(cX:Number,cY:Number,r:Number,col:Number,eX:Number,eY:Number,rX:Number, rY:Number):Sprite{
    var c:Sprite = new Sprite();
    c.x = cX;
    c.y = cY;
    with(c.graphics){
        beginFill(col);
        drawCircle(0,0,r);
        drawEllipse(eX,eY,2*rX,2*rY);
        endFill();
    return c;