Hi Tuan,
OK - I might be able to offer some additional info here
Having sent may last response I thought I would go and try a Dropbox connection - and it worked!
Clearlly, at this point you have to upload the file directly to dropbox and then place the file specific link URL in the eDocman configuration setting. Having done this, althought no file "details" are available, the linking process works!
I dont know Dropbox well enough, but for an mp3 file, the only option dropbox displays is a download option - ideal for my use in this senario.
When and if you do get around to an off site storage option (Dropbox, S3 etc.), as I said before I can see that being REALLY popular!
if you want testers, or any other input from me please just ask...
Menawhile I will let you know if I find any other "wrinkles" in the process