ultraVNC - Running in Embedded (tabbed) Mode

Is it possible to run ultraVNC in a Tab, using the embedded/tabbed mode, like an RDP session? I am using RDM 5.7.3.0 and ultraVNC 1.0.8.2. An imported .vnc file creates a a session in External mode. Activating the session yields an external VNC Viewer Status box, then a VNC logon box, and finally an external VNC windows as expected. After editing the session from External to Embedded (tabbed) mode, activating the session yields a RDM error box stating "Unable to connect to host!" I was able to get a little closer by creating a command line session using ""C:\Program Files\UltraVNC\vncviewer.exe" -connect <host>" as the Run command. The initial VNC Viewer Status box ran in a Tab, but I again got an external VNC window. I got the same experience using ""C:\Program Files\UltraVNC\vncviewer.exe" -config <filename>."

I even tried changing the authentication procedure between the default vnc password (weak) method, the New MS Logon method, and the Require MS Logon (preferred) without any change.

My goal is to have RDP and ultraVNC sessions working within the tabbed framework. Am I missing something or just asking to much? I'd appreciate any help or comments. Thanks in advance.