Here is the source code so you can try it yourself. But you don't have to. Be sure to tell me what you are doing. Your test file should have several occurrences of a money amount. I've done something similar with Web pages in my JustLinks applet with the engine.
Spots really are objects.
It is the spot's, not the applet's, responsibility to know how to draw itself. You will create an applet that will draw more than one spot on the screen. A spot is drawn when the mouse button is pressed. The spots will have nice colors, nice shapes and nice sizes. This is a bigger project.