You don't. The H screw limits how far from the bike the hanger can move, and the L screw limits how close it can get to the frame.
............................
Now you've done that, still on the smallest 'ring, get some pliers and an allen key for your front mech cable. Loosen the allen key that is gripping the cable a little, just enough so you can pull the cable through. Hold the loose end of the cable (the bit that sticks out of the derrailleur and ends) with the pliers and pull it so it is tensed. Now tighten the allen key and you should be shifting nicely, if you need to, you can adjust more finely with the barrel adjuster.