If I were to do simple macro type automation, then I'd record it within Excel or use the existing VBA and save myself the pain of OLE.
I don't want to sound overcritical, but wanted to point out two potential problems with having Perl calling macros in Excel.
First, Excel 2010 defaults to not enable macros. That means you'll probably have to add code to enable the execution of macros. Since I don't have Perl calling macros, I personally have not encountered this issue myself. That default behavior might be changeable, but I personally think that it's not a good idea to make assumptions about what settings are for a program like Excel when developing code and manipulates that program.
The second problem is related to something actually happened at work. My first dive into learning Perl was to generate Excel charts. A coworker previously had a script that did this and his called macros. My coworkers were emphatically telling me to not use macros when they found out what I was working on. What happened was my coworker's template Excel file got corrupted with a virus. So when folks used his script, the macros was deleting files, which wreaked havoc on projects. Therefore, I made sure that my code was not using macros and was not relying on a template Excel file.
Again, it's a matter of personal preference. However, I would strongly urge folks to not call macros from Perl, but rather convert the macros into Perl code for your Perl program to use. I realize that doing so means more work, but I personally feel the benefits of doing so are well worth it.