Select the anchor options, will automatically put '^' or '$' or '^$'. you're allowed to put only once per regex string (that's the regex rule, isn't it?).
But there's a few bugs i.e. if you create sub regex, you can create something absurd like this ' /^item(^duhduh$) foo$/'. i'm still looking into it. sorry for that.
(i hold this quote for a while...)