Mmmmm, I don't know exactly what you want since <ESC> pause video and game.
If you want, in Pete's OpenGL2 Driver 2.7, Pete's OpenGL Driver 1.76 and Pete's DX6 D3D Driver 1.76 configuration screen, there is a small button ( marked ...) near frame rate control. There, you can assign a key to toggle pause.
Greetings.