Macros are Freemarker macros - see http://freemarker.org/docs/ref_directive_macro.html
Here's an example of a macro we're using in one of our applications:
As you can see, it contains a mixture of Freemarker and OpenDocument markup - generating several paragraphs of text from a data structure.
Since "Create OpenDocument" only creates the file, and doesn't run OpenOffice, there's no way to run OpenOffice macros in it. What might be possible it so somehow include in the tempate an OpenOffice macro that runs every time the document is opened. I don't know if this is possible in OpenOffice.
For best results, use the Firefox browser..