What is ODMA?

Apart from that, "opening a file" in Windows is really an abstract act: it can open an actual, local file, or a remote file via various protocols, or a dynamically-generated resource of some sort.

I think that you have installed some driver that tells Windows how to handle file requests in the form ::ODMA\.

Perl's open can only access local files. You can try using Win32API::File's functions createFile and OsFHandleOpen to open a Perl filehandle to a generic resource (NOTE: I don't use Win32, so I can't guarantee that this will work)

-- 
        dakkar - Mobilis in mobile