Change Wording on Registration Page

At the bottom of the form, I would like to change "Register" to "Proceed." Just think it's more intuitive. The click is a button, and usually I would look in the en-BG file to make the switch. But it's not there, at least that I could find. Can someone direct me to the correct file? I am attaching screen shot.
-Jim Gribble

It's on the line 1011 of the english translation file:
HIKA_REGISTER="Register"