[Jonathan de Boyne Pollard]

You're thinking of Microsoft Office and SharePoint.  It is they that enforce behaviour like the above, not Win32.  They also agree on private application-level mechanisms such as "owner files" (q.v.).  How one retrives such application-specific information is, of course, application specific.  With WebDAV file locking, for example, one calls the DavGetTheLockOwnerOfTheFile() function in the WebDAV API.



Yes, I am trying to find something in Microsoft Office that will possibly let me enumerate through each user who currently has access to the current document.  [...] Nobody in the Office boards knew any "application specific" solutions,  [...]





Then get them to tell you about owner files.  Or just look up the concept in the MS KnowledgeBase yourself.  (-: