I think punctuation is probably stripped out of the search strings. One thing you can do is download a PDF of the scriptures from LDS.org (because it has all of the chapters and verses in the same document) and doing a search in Preview or Acrobat or whatever you use to read PDF files for "?". It may take a bit to search depending on the speed of your computer. I know there are some plain-text files of the scriptures floating around online that may be faster to search, but I don't think the church has any plain-text versions published. It's fun to search the Bible for emoticons like ":)" or ";)" too...
Samuel Bradshaw • If you desire to serve God, you are called to the work.