I don't think you can.  The new server knows nothing about the data on the
other server's volumes.

I'm afraid you're going to need to remove the client from the new system,
import the data from the old and then start backing up the client on the
new server.  Problem with that is you lose the data between the last time
it was backed up on the old system and now.

I think this is in the category of "Dr., Dr., it hurts when I do that!
 Then don't do that."

Kelly