Shortcut key to accept Policy Banner?

I'm a technology support specialist with a municipal school board. The vast majority of our workstations are Macs using 10.8.3, and are set to display a policy banner before login. Typically, this isn't a problem, but I'm particularly in charge of support for a division of the school board specializing in visually-impaired students. Because the policy banner only has the tiny little "Accept" button at the bottom, the students have some issue finding it and clicking on it. I cannot seem to find any way to press the Accept button without using a mouse.

Does anybody know if there's a keyboard shortcut to dismiss it, or a method by which to modify its properties so that it has a default key? I'm more than happy to tear into the roots of Mac OS X and change major things, if necessary, and I am no stranger to the Terminal. Although I've not gone digging for it, I'm certain there must be some setting somewhere that determines the default size and properties of the Accept button, and thus I suspect there must be some way to map a keystroke to it. Security and legal considerations prohibit the possibility of just removing the policy banner.