Help with a macro

I want a macro for use in COD:MW that when I press the left mouse button, it goes ADS and fires until I release the button. I know I will have to assign the left-click to another button before I can apply a macro, but I'm having trouble creating the macro. I created one for my old Logitech mouse, but of course the options between the two programs are completely different. Currently using the Basilisk V2. When I try, it just either keeps firing until I'm out of ammo or will seem to burst fire