Looking at the numbers on the remote control, they've got letters assigned just like a telephone pad. If you go into 'search for shows', when you get the alphabet layout on the screen, press the number '2' on the remote. You'll see an 'a' appear. If you quickly hit '2' again, you'll get a 'b'. Hit it again, a 'c'. If you wait a couple of seconds, it'll move over so you can start 'tapping' the second letter, or if you press a different number key other than '2' it'll also move along.
For people used to using their phone keypad in this manner for texting, this is second nature. I'm not a texter but I've gotten used to 'typing' in stuff this way. Its a hell of a lot faster than hitting 'left/right/up/down' a hundred times and waiting for the cursor to catch up.