replacing some special characters

[Pete Siemsen]

I have a buffer that contains mostly normal characters, but has some weird 
characters.  I simply want to replace all occurrences of the weird characters 
with spaces.  I'd like to use replace-regexp to do it, but I don't know how to 
specify the weird characters.  When I place the cursor on one of the weird 
characters and execute describe-char, I get

        character:   (160, #o240, #xa0)
preferred charset: unicode (Unicode (ISO10646))
       code point: 0xA0
           syntax: .    which means: punctuation
         category: .:Base, b:Arabic, j:Japanese, l:Latin
      buffer code: #xC2 #xA0
        file code: #xC2 #xA0 (encoded by coding system utf-8-unix)
          display: by this font (glyph code)
    nil:-apple-Menlo-medium-normal-normal-*-12-*-*-*-m-0-iso10646-1 (#x62)
   hardcoded face: nobreak-space

Character code properties: customize what to show
  name: NO-BREAK SPACE
  old-name: NON-BREAKING SPACE
  general-category: Zs (Separator, Space)
  decomposition: (noBreak 32) (noBreak ' ')

There are text properties here:
  fontified            t


I've tried using \o240 and \xA0, with no luck.  How can I get replace-regexp to 
match the special characters?

-- Pete