counting documents with specific attribute

Hello,

Is there any way to count the resources in a collection based on a
specific attribute within those resources?

For instance, I have a collection of resources in the form:
<DOCUMENT>
	<STATUS value="1"/>
	...
</DOCUMENT>
where STATUS/@value can be 1, 2 or 3.

I have also created an Indexer with pattern "STATUS@value".

e.g. Is it possible to ask the Indexer how many resources have
STATUS/@value=3?

thx,
Matt