Hold SHIFT on and off with another key press

[soopytwist]

I'd like a script so that when I press LEFT CTRL once, the LEFT SHIFT key holds down permently until I press LEFT CTRL again and the LEFT SHIFT key is released. This must be repeatable. I will run the script only before playing some games that don't allow toggle buttons, so once I'm finished in the game I need a way to turn the script off.

The LEFT SHIFT must be able to function as normal though (until I press CTRL). I don't know much about scripting so please be clear, thanks.