OpenOffice saves this parameter in the template (File-Templates).
If there is one (File-Templates-Edit) - just open it, change printer setting and save.
If not, create one (create just new document, change printer setting and save it in the dir, named in Tools-Options-Paths-Templates) with OpenDocument Text Template(.ott) extension. After that, File-Templates-Organize, DblClick on MyTemplates (it folds out), then right-click on your just created file-template (it appears here) and choose Set As Default.
I'm not sure it's the easiest way, but it works.