title: powershell: how to evaluate a string
body: <p>file a.txt is:</p>
  
  <p>delete from test_$suffix</p>
  
  <blockquote>
    <p>$a=get-content a.txt</p>
    
    <p>$suffix="tableA"</p>
  </blockquote>
  
  <p>how to manipulate the variable to set it as</p>
  
  <p><strong>delete from test_tableA</strong></p>