if you have the latest adobe acrobat (not the reader) , you can automatically convert your doc file to pdf in just one click.
just download cutePDF writer install it.It vl directly install component for the Microsoft doc conversion.
when you install Adobe PDF, an image creator will be install as a printer so just go to print, and then choose to PDF creater as the printer. Then you can change it in to PDF
Here you go I've taken the liberty to point the arrows to quick button and the File/Export as PDF option. You can use either.
Try this http://offersforyou.blogspot.com/2006/10/convert-pdf-to-word-document.html. It also has free trial offer.
THE PDF option is not at the Open Office Doc dialog but rather in the Menu as I have indicated above. By the way, which version of Open Office do you have ?