title: Remove all non-numeric characters from a CString
body: <p>I need to format a CString that contains a phone number.</p>
  
  <p>I need to remove all spaces and all characters that are not a number.</p>
  
  <p>Please advice on how I can do this.</p>
  
  <pre><code>tel1 = replace(tel1,' ','')
  </code></pre>
  
  <p>That is how it would be done in C# but I don't have a clue how to do it in Clarion.</p>