How to script "add to iTunes Library"
On the Mac side, you can create a DMG file with Disk Utility. Once started you can either select "New Image" to create a an empty one or use &#x21E7;&#x2318;N to create an image based on a folder.

To copy the audio files to iTunes, it's probably easiest to just move/copy them to ~/Music/iTunes/iTunes Media/Automatically Add to iTunes (may be called differently, just look at the folder first) and let iTunes (which must be running) do the rest.