title: Copying specific columns from one datatable to another
body: <p>This doesn't seem like something that should be confusing or difficult, but I'm having a hard time finding the answer to this problem. I want to copy columns with their data, not rows, from one large DataTable to a smaller one.</p>
  
  <p>I have a DataTable with many columns of data (around 20), and a string array of the columns (4 ) that I want in the copied DataTable. Is there a reasonable way to accomplish this task? </p>