There are at least two ways to do this (off the top of my head)
1. The hackish way:
a. I’d probably put up a cvs version (since the sqlite db is easier to modify and manipulate) and get a database of your “at home” file layout.
b. Once you have that, set up the same version at work. Copy in the database from home. In dispatch.c, on about line 695 it does an open from the file info from the path. Rather than a fopen on the path from the pmp3 struct, you’ll be constructing a url (http://your.server/databases/1/items/%5Bpmp3->id].mp3) and feeding that back to the client.
It’s a single-purpose hack, but not to difficult. Just make sure the db is in sync with the home database, and start up mt-daapd with a -s (skip initial mp3 scan) and scan_interval set to 0.
That should work.
2. tcp/ip tunneling over http?