If there is a document associated with the item in the document library, those fields should have values in them (for example, EncodedAbsUrl is exactly what it sounds like, a URL encoded string with the full, absolute path to the document on your SharePoint server).
*Every* SharePoint list and document library has fields that are not visible from within the UI, I just want to know how I can get access to them for use in my qListView. If the CAML Filter property of the web part allowed me to define the ViewFields property of the SPQuery object and not just the where clause of the Query property, I could handle it that way, but it does not.
I can work around the absence of EncodedAbsUrl by creating a <custom> field that combines the folder and file name, but it's annoying to have to do that when I know full well that the value I am looking for is already in the list but not available to me through the web part I am using.