FIND/REPLACE UNICODE ZERO-WIDTH CHARACTERS
To find and replace hidden Unicode (UTF-8) characters in filenames, use the regular Expression \uXXXX where "XXXX" is the Unicode identifier. A good resource to lookup UTF-8 codes is https://www.compart.com/en/unicode.
See this forum post for a more thorough discussion on using Unicode with Dopus renaming and scripting.
Thanks to Leo for the solution.