How to run xquery dynamically on file listing from directory

[seleneplatt at comcast.net]

I'm a complete newbie at xquery and am trying to execute a query dynamically on 
all files in a given directory, rather than hardcoding a particular file into 
the 'doc()' call.  I've tried using 'collection()' but am unclear as to how to 
get it to work.

I did see this thread on x-query.com:
 Query Through Multiple Files
but the closest anyone came to the answer I was hoping to find was to hardcode a 
*list* of files to traverse.

Is there anyway to do something like:
    for $x in collection("xmlfiles")
where 'xmlfiles' is a subdirectory containing the actual xml files I want to 
use?  I would need to know the exact syntax, as this is all new to me.

Thanks!