If you're on a Windows box with Excel installed, I'd recommend that you use Win32::OLE to use Excel directly. You can use the OLE browser that is part of the module as well as recording a macros and looking at source code to help you figure out your tasks. Unfortunately, both will be in VB, so you'll have to convert VB to Perl.

Basically, I've found that using Win32::OLE, you can use Perl to do just about anything that you can do in Excel manually with a mouse and keyboard, including the things that you're wanting do.

If you're not on Windows, you might try looking into doing something similar with Open Office.