Hi Jim, thanks for the respond, but could you elaborate a bit more?
I tried mc20.exe "/Play %1 /Mode Fullscreen", not working.
My current difficulty is not that playback does not start. 'mc20.exe /Play "%1"' works and starts the play back in JRiver.
However, this command returns immediately, so the caller application resumes, in case of XBMC and other caller environments, the caller window pops back up top and grabs the focus. Other players MPC-HC, VLC etc only returns when the video is finished or the user issues a stop (from keyboard or remote).
Is there something to the effect of mc20.exe /Wait, which waits for the current playing program to finish before return? much like waiting for a separate thread to rejoin. for a movie this means /Wait would hold on to the command pipe line for hour and half and prevents the return to the caller.