title: How can I modify an existing Excel workbook with Perl?
body: <p>With <a href="http://search.cpan.org/perldoc/Spreadsheet::WriteExcel" rel="noreferrer"><code>Spreadsheet::WriteExcel</code></a>, I can create a new workbook, but what if I want to open an existing book and modify certain columns? How would I accomplish that?</p>
  
  <p>I could parse all of the data out of the sheet using <a href="http://search.cpan.org/perldoc/Spreadsheet::ParseExcel" rel="noreferrer"><code>Spreadsheet::ParseExcel</code></a> then write it back with new values in certain rows/columns using <a href="http://search.cpan.org/perldoc/Spreadsheet::WriteExcel" rel="noreferrer"><code>Spreadsheet::WriteExcel</code></a>, however. Is there a module that already combines the two?</p>
  
  <p>Mainly I just want to open a <code>.xls</code>, overwrite certain rows/columns, and save it.</p>