[Olli2k]

@ syrn
That depends on the hoster and their function/restriction on the ddl option. I think for example rapidshare links, with enabled ddl might work, but i have not tested it yet.

@ lemonadesoda
ok, now i understand your intention. I did'nt test this solution, but it might be possible that you can use a "member" ftp link like ftp://usernameass@hostnameort/path/to/mp3//file.mp3.
Another possible solution can be a htaccess protectet folder. But everyone who wants wants to use the MP3 urls in this folder, needs a htacess login.
For a really secure and vbulletin based system, it might be possible to use a database system like donwloads2. You can select a database storage filesystem, so the files can not be found on a open web server location. After Uploading Files to the Database you can use the downloads2 links for the BB Code Player.

But i say it once again: nothing is tested yet.