selectSingleNode changes needed with DomDocument60

Hi,

This is my XML:

<?xml version="1.0"?>
<Revision>
    <Revision Index="1"/>

</Revision>

When using DomDocument(ver 3) I could run the following(In VB6):

Set objNode = objDom.documentElement.selectSingleNode("//.[@Index = '1']")

This is to identify that this attribute exists with it's value.

Now after moving to DomDocument60(ver 6) this line fails.

How should I re-write it so it works with DomDocument60?

Thanks in advance

Doron