How to restrict user to have a single session for RemoteApp or Remote Desktop connection.?

I have a windows server setup, which has enabled RemoteApp. As a user, he can connect to RemoteApp or full desktop (RDP).

1) Let say user1 connects to app1 from client machine. The desktop session (Ex: session id -> 2) is created.
2) Now user1 closes the app1. The session will be in disconnected state.
3) Now the same user (user1) does RDP to the server, and here new session is created for same user.  (Ex: session id -> 3)
(can't reuse the existing disconnected session?)

Here the terminal server (RDSH) creates different sessions for Remote Desktop and Remote App connection. 

Is there any way so user1 should connect (RDP) to the disconnected RemoteApp session i.e id (2)instead of creating new session?  The setting "Restrict Terminal Services users to a single remote session"does not help here.

Thanks..