the problem is not with the key, cause he is able to turn the key all the way, the trouble is the switching mechanism inside the ignition, or cut or loosestarter wire on the ignition harness. if everything works when you turn the key, and just not the starter, and you are sure the problem is in the ignition, I can tell you how to do a push button. I did it inmy 05 civic. I'll just tell you the simple way, so you will still need to turn your key to on, cause to do it without a key, is way harder for me to explain over the internet. All you need to do, is tap into the big white wire in the ignition switch (constant +), and the big Black/White wire in the ignition switch (starter wire), and hook it up with a relay and a push button. I drew a diagram, so if you want me to send it to you, send me your email addy.
Here is mine....
