title: Excel compare two strings and return the number of unmatched characters
body: <p>I want to compare two strings, and the return value is the number of unmatched characters.</p>
  
  <p>For example:<br>
  A1: abc<br>
  B1: acde<br>
  The cell B1 is compared to A1 and will return 3.</p>
  
  <pre><code>A1: abc
  B1: a cde
       * **
  </code></pre>
  
  <p>This application is for multiple choice question with more than one answers.<br>
  A1 is the correct answer, and B1 selects 3 wrong answers.</p>
  
  <p>Is there any way to accomplish this task?<br>
  Thanks!</p>
  
  <p>--<br>
  Sorry for my unclear words. <br>
  Assume the question has 5 choices (abcde), and A1 is the correct answer. <br>
  B1 is the answers selected by someone, and he/she selects 3 wrong answers.</p>