In addition to http://www.xml.com/pub/a/2006/01/11/from-microsoft-to-openoffice.html?page=1 I would recommend this http://www.oooforum.org/forum/viewtopic.phtml?t=3549
Putting these two together gives you pretty much everything you need to (i) figure out what formats you can export OpenOffice content to, (ii) invoke OpenOffice to do the export, and (ii-a) how to use OO Basic macros within OO to coordinate the process.
It'd be ideal to get this encoded into a Perl module for CPAN. Yet another "wanna do" project on the stack. ;-)