title: Google Sheets Pattern Matching/RegEx for COUNTIF
body: <p>The documentation for pattern matching for Google Sheets has not been helpful. I've been reading and searching for a while now and can't find this particular issue. Maybe I'm having a hard time finding the correct terms to search for but here is the problem:</p>
  
  <p>I have several numbers (part numbers) that follow this format: <code>##-####</code></p>
  
  <p>Categories can be defined by the part numbers, i.e. <code>50-03##</code> would be one product category, and the remaining 2 digits are specific for a model.</p>
  
  <p>I've been trying to run this:</p>
  
  <pre><code>=countif(E9:E13,"50-03[123][012]*")
  </code></pre>
  
  <p>(<code>E9:E13</code> contains the part number formatted as text. If I format it any other way, the values show up screwed up because Google Sheets thinks I'm writing a date or trying to do arithmetic.)</p>
  
  <p>This returns 0 every time, unless I were to change to:</p>
  
  <pre><code>=countif(E9:E13,"50-03*")
  </code></pre>
  
  <p>So it seems like wildcards work, but pattern matching does not? </p>