title: MFC, OPENFILENAME structure: m_ofn.lpstrCustomFilter
body: <p>I'm just trying to figure out how to use <code>m_ofn.lpstrCustomFilter</code> in MFC's <code>CFileDialog</code>.</p>
  
  <p>The internal structure is a <code>OPENFILENAME</code>.</p>
  
  <p>I need a practical example, as all examples I have found are setting <code>lpstrCustomFilter</code> to NULL.</p>