I use Innerspace, which is easy to set up mouse broadcasting in AoE macros. It has a reoccuring charge though. (worth every penny in my opinion)

Someone else had an addon here where it could use a mobs nameplate to move the mouse, and you would just need to bind a key to the click to pass it to the other character. It is here http://www.dual-boxing.com/showthread.php?t=29050