Multicaret editing is interesting idea. But i am afraid not easy to do, cause Windows control doesn't support more than one caret. But I will try to do it.
In the program settings / Editor 2 you can set shape of caret for insert and overwrite mode -- <http://forum.pspad.com/read.php?2,62599,62603> PSPad freeware editor http://www.pspad.com
