title: Write an array in specific column by Pandas to_excel
body: <p><code>pandas.DataFrame.to_excel</code> documentation says column is  optional Columns to write, but I'm wrong, how should the specific column (e.g. column J) be defined?</p>
  
  <pre><code>import pandas as pd
  my_array = [0 for i in range(len(data))]
  pd_array = pd.DataFrame(my_array)
  pd_array.to_excel(r'C:\Users\my_dir\SandBox.xlsx', sheet_name='Sheet2', columns = 8)
  </code></pre>