Linux has an file system wrapper thingy called
cifs that allows it to mount an SMB share (Windows shared folder) transparently as a standard folder to the file system.
Looks like there's an android app for creating and managing cifs mounts - CifsManager. Using it, I assume you could make your Android device see all the files in the shares just like they would be on your memory card. The app does list "playing music" as an example use case in it's description, so I expect it could be used for this purpose.
I haven't looked at how it works yet, but intend to now that you made me interested in the use case. :) I'll edit the answer when I've had time to test this.
Note that the app requires root. Also, don't know if it can automatically reconnect the shares when they become available. And I'm not sure if it messes up the Android music player or file management system or whatever if the mounted files it was accessing suddenly become disconnected (I would expect that Android can handle it, though).