Have just spent the last couple of days trying to process a spreadsheet file created in openoffice using perl. The problem I had was deciding which CPAN module to use. A choice of one which did everything I wanted would have been ideal. Unfortunately I had the overwhelming choice of hundreds.
I finally settled for ODF::lpOD
Thanks to the following pages that pointed me in the right direction:
how-to.wikia.com/wiki/How_to_read_OpenOffice_OpenDocument_spreadsheets_in_Perl
search.cpan.org/dist/ODF-lpOD/lpOD/Tutorial.pod#Individual_cell_access,_read_and_update