Library bitmaps / string / class

1

i have a bitmap in the library with export name Dots

how do i take this and pass it to the class which expects a Bitmap as a parameter?

if i load it externally i could say:

var bmp:Bitmap = Bitmap(loader.content);

and pass it to the class.

i tried this but no success:

var c:Class = getDefinitionByName("Dots") as Class;
var bmp:Bitmap = new c(0, 0) as Bitmap;

i have a string var which will hold these library bitmap names, for example:

var myString:String = "Dots";

how do i do this from this string:

sprite.graphics.beginBitmapFill(new **Dots**(0, 0));