This bug isn't due to a mis-toggled setting that can be switched with the API, it is due to the file itself being more "closed" than it should be (at least that is my suspicion). SolidWorks Corp is the only one that can "open" the file to make its custom properties viewable in Windows Explorer.
The workaround, I imagine, would be to search for the these database numbers within your PDM system. If you don't have a PDM system, or one that can't view SolidWorks custom properties or use them as a search criterion, then you're only resort would be to write your own mini-PDM system using the Document Manager to search for models in a given directory according to a specified custom property. If you need to go that route, visit my site below. I can offer very fast turn around.