I've been playing around with this one by Erik A. Dewey
which does translate quite a bit into LibreOffice. I haven't thoroughly looked to see how accurate it does. I know one major hang up was a feature with a drop down list for Classes, but I found a work around by simply entering the number that designates that class found in the Data page.
I don't have a lot of experience creating spreadsheets of this kind of complexity with any of the flavors (Excel, OO/LibreOffice, Google Docs). Is something with that much interwoven formulas even possible with Google Docs?
*edit- the above link is referring to the Spycraft 2.0 sheet