Access to XSD annotations from VBA

Hello,

I'm currently using MSXML6 from VBA (Excel 2007), and I can't find a way to access the "annotation" nodes nor "appinfo" or "documentation" of an element for example:

<xs:annotation>

  <xs:appInfo>W3Schools Note</xs:appInfo>
  <xs:documentation xml:lang="en">
  This Schema defines a W3Schools note!
  </xs:documentation>
</xs:annotation>

Using the debugger, I can browse my ISchemaElement, but can't find any object which contains the annotations. Am I missing something? How to read those annotations?

Thanks in advance.

Nicolas