you (the external) somehow must link the mouse position to the OS browser. well, maybe that is possible (just as screen recording once was possible with nato)
but what do i know about externals. the only thing i know is that it can be wise to remain sceptical. about everything. :)
i remember well how baffled (or better amazed) i was when i found out that the drag and rop manager in mac os 7 allowed to drag and drop layers of pictures files directly between photoshop 3 and graphic converter.