title: Linq: select where in List<string>
body: <p>Struggeling with some LinqToExcel filtering here...</p>
  
  <p>Ive got a <code>List&lt;string&gt; columnsToFilter</code> that contains 9 strings, and with that i want to filter out the data for certain columns in a <code>List&lt;Row&gt;</code>, where <code>Row</code> contains the properties </p>
  
  <pre><code>IEnumerable&lt;string&gt; ColumnNames
  Cell this[string columnName]
  </code></pre>
  
  <p>So: <code>List&lt;Row&gt;</code> has say 30 rows, each having 12 ColumnNames. Now i want to filter that <code>List&lt;Row&gt;</code> using <code>List&lt;string&gt; columnsToFilter</code> so that i end up with a <code>List&lt;Row&gt;</code> of 30 rows and <em>9</em> ColumnNames.</p>
  
  <p>I can select the data for <em>one</em> column by quering the columnname:</p>
  
  <pre><code>var result = content.Select(m =&gt; m["Column1"]).ToList();
  </code></pre>
  
  <p>Now i want to filter the data based on a <em>List</em> of strings <code>List&lt;string&gt; columnsToFilter</code>. Whats the best way to achieve that?</p>