The closest thing to what you need I think is the uuid_hold command
However, I don't think you can still receive audio from the other end. The hold_music channel variable will let you configure the hold music.
Another way of doing this would be place your caller in a conference and use the conference api's to deaf the member and play hold music to just that member. I'd do this if I really need to receive audio from the caller's channel and if there is no other way of doing it as I'm not sure a conference is a good idea for a two person call.
Nishad