Cats in general can be tricky, and this sound like an extra tricky problem on top of that. I have 2 ideas. 1) Maybe try playing with them more to get more energy out so they wont want to go after the computer mouse. 2) Give him something more entertaining. Like "cat tv" which could literally be a cat channel on another tv/monitor, a bird feeder or something outside of a window for them to look at, or (something I wouldn't normally suggest but in this case who knows) one of those self moving laser pointer things. Other things that might keep your cat busy is some kind of pet puzzles or toys that you hide treats in and they have to figure out how to get their snack out.
It sounds like you have a smart, high energy kitty. I understand how difficult it is to deal with a smart cat (mine figured out how to open doors too), luckily mine is fairly low energy most of the time though. You might need to help get some of their energy out more. To cats even watching things move around takes energy, like they are planning their move and stuff. So sounds like he's using the cursor to watch like prey because they still have a lot of energy. IDK if you have heard of Jackson Galaxy, but he has some youtube videos and stuff that might help give some other ideas to for the "cat tv" idea.