There is an add in called golden cursor.

You will need sighted assistance to place the mouse where you want to mark.

Its been a while since I used it, so would have to review how it works.

Also, I took a usb mouse and covered the mouse part on the bottom that
tracks the pointer around and use it just for clicking on things,

This makes it very easy to use and you don't have to worry about moveing
the
pointer around when you don't want it to move.