Level 3 Fallen at the first fence

I jumped ahead of myself and have prepared a regex which i believe will work. When i come to apply it to the code there are no letters, i know I am being REAL dumb and my forehead hurts from where it hit the keyboard. Could some kind soul give me a nudge in the right direction.

Thanks

Forget the above I walked away for a few days come back and realised I was on some other plane that day