title: Write dataframe to excel with a title
body: <p>I would like to print out a dataframe in Excel. I am using ExcelWriter as follows: </p>
  
  <pre><code>writer = pd.ExcelWriter('test.xlsx')
  df = DataFrame(C,ind)    # C is the matrix and ind is the list of corresponding indices 
  df.to_excel(writer, startcol = 0, startrow = 5)
  writer.save()
  </code></pre>
  
  <p>This produces what I need but in addition I would like to add a title with some text (explanations) for the data on top of the table (<code>startcol=0</code> ,<code>startrow=0</code>).</p>
  
  <p>How can I add a string title using ExcelWriter? </p>