[xsl] counting the preceding cousins of an element

[Carlo Liwanag <cliwanag@xxxxxxxxxxxx>]

Hi,
I am trying to get the number of preceding cousin of an element but I 
can't seem to work on it.
I tried using the axes but I guess it could not reference the same 
ancestor. For example,
<chapter>
   <para>
      some text here
      <footnote>
          some text here
      <footnote>
   </para>
   <para>
       some text here
      <footnote>
          some text here
      <footnote>
      some text here
      <footnote>
          some text here
      <footnote>
   </para>
   <para>
      some text here
      <footnote>
          some text here
      <footnote>
   </para>
</chapter>
<chapter>
   ...
</chapter>
<chapter>
   ...
</chapter>

In this example, the footnote is the element and the ancestor is the 
chapter.
How can I find the preceding::footnote[ancestor::chapter[descendant::"is 
the current node"]]?

Thanks,
Carlo