probably a simple JitterObject question

I am drawing a scene within Java using jit.gl.sketch and jit.gl.render as JitterObjects. However I want to be able to interact with the jit.pwindow I'm drawing to.

I can get the mosue positions but am unsure of how to change these to world coordinates within java.

Outside of Java I would simply pass the message "screentoworld $1 $2" to the jit.gl.render object with $1 and $2 being the screen coordinates. I would then get the world coordinates from the 'dumpout' out of the jit.gl.render object.

How do I do this in Java though?

any help would be much appreciated, thanks.