you only need a dot, dose not even have to be a level, a laser pointer can work, but eye ball it and get it as close to level as possible and parallel with the bolt. You bike needs to be on a rear stand, or propped up on something so that it straight up, you can lean the bar up against a wall if need be just until you get the faring marked.
take the fairing off, set up the bike and align the laser so that it points dead center of the bolt. without moving anything put the fairing back on, you don't have bolt it on, but it needs to be where it goes. Get a sharpie and mark the laser spot.
a laser that gives you a line wont do you much good, you either need a dot or two lines.