I am not sure how you would fix that without poking around
and it is late here.
The lack of answers so far suggests perhaps you cannot.
Perhaps you could consider a third party search tool such as
Zoom from
http://www.wrensoft.com. I have
seen it implemented with a search page as a
topic accessed from a toolbar button calling that topic
instead of the RH
contents button. It's quite straightforward to set up and
inexpensive.
You can see it working on my site.