[bdbxml] How to check for substring without specifying any particular node

Hi
I am putting up a default index like this:
Default Index: node-element-substring-string node-element-equality-string

Now, I want to query the container, so that I ONLY specify the value and not 
specify the node. So, that way, I am basically checking out for any 
available text which matches this string. 
But, using the dbxml shell, I have to specify the node name; otherwise, it 
doesn't retrieve any docs.
Is it possible to retrieve docs in the above mentioned scenario? Or, any 
otherway to do so?

Regards
Manish