Apologies for "coming late to the party." While I don't have a complete solution for you, I'd like to share some things that may help.

I believe the advice you've already been given re: Win32::OLE is sound. You will want to use something like: rng.Formula (VBA; where rng is a Range Object that can refer to single or multiple cells) to access a cell's formula (the =56.43+45.31+34.41 part).

I think you might benefit from replies to the thread VBA to Perl; marto has some great links on translating VBA to Perl, and I've got a few references to some utilities as well.

An indispensable site for all things Excel- and spreadsheet-related is the aptly-named Spreadsheet Page, by John Walkenbach.

Oh, and AFAIK, OpenOffice should be every bit as accurate as Excel. :-)