Unique IDs for notebooks?

The scenario: There are hundreds of different notebooks on the disk all over the place, and these notebooks form a web, by means of hyperlinks. Not all notebooks are open simultaneously in a OneNote session. Now, "onenote:"-hyperlinks work fine, as long as one doesn’t move notebooks around. If one does, then they break! So: Can one give a notebook a unique ID (somewhat like a URN != URL) and link to it using that ID? If not, would it be possible to write some kind of extension for that purpose? - Felix PS: If that’s not the case, I’ll consider the following solution/ workaround which resembles something I’ve implemented in a different environment. Put the ID on a page called "UNIQUE ID" in the notebook. Link to notebooks using URLs that point to files hosted by a local web server. When one opens such a file, an application is started that searches the notebook with the given ID and opens it in OneNote. A simple caching mechanism w...