How to set bibliographic entry to display author only when applicable?

I'm writing my bachelor's thesis with OpenOffice Writer. Most of my sources are websites, and the author or publication year is often absent.

With Writer's bibliography system, you can specify whether to display author, publication year etc. for a certain type of entry, eg. WWW document, but the same settings will be used for every WWW document (whereas I would like to have the author displayed when and only when applicable).

I know there are "user-defined" entries, but this system seems a bit clumsy, as you can't rename them from "User-Defined1" and so on.

I think MS Office Word has a better system, but I've heard that the open-source alternatives are just as good, so why buy it? I've also tried Zotero and Mendeley, but it seems they can't display inline citations in the [1][2] style, which I would prefer.

Would rather avoid using LaTeX/BibTeX, since they seem like overkill.