Unfortunately, it's not possible to connect to a remote Host/Agent without adding it's IP address or Internet-ID code to the address book as a connection first. The Agent module is designed for spontaneous support, so that remote session is only possible while Agent is running on a remote machine. However, it's still required to add the Internet-ID/IP address as a connection in the address book in order to establish a connection to the Agent using any of the connection methods. However, the connection can always be removed from the address book as soon as the remote session is over.
I'm sorry if this makes the program less useful for you.