cassiano's dashboard

XML export: Is it possible to select which fields to export? I wanted to export a very simple XML file, something like this:
<book>
<title>the title</title>
<author>author's name</author>
<book>

Is this possible? At the export XML windows I see:
"Create a custom XML document with your media... [snip]"
How do I do that?
Thank you in advance,
Cassiano</book></book>