I see you found my code! http://www.oooforum.org/forum/viewtopic.phtml?t=100205 - How to program OpenOffice Calc using Perl API w/ OLE and DDE http://stackoverflow.com/questions/278090/how-can-i-create-or-read-openoffice-spreadsheets-from-perl/2780194#2780194 - How can I create or read OpenOffice spreadsheets from Perl? If you look down a bit more, you'll see how to hide the window:

# How to hide, as loading the document hidden does not work. 
$calc->getCurrentController->getFrame->getContainerWindow()->setVisibl
+e(0);
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