Noone is going to just hand over the entire source code for such a large project.
It is not as easy as you think it is. You need intimiate knowledge of how Windows works, how the Shell works, plug-in support in your own application, writing and exposing an API that thes plugins would use to interface with your SideBar, ..., yada, yada, yada...
You need not use cmd.exe as it the command shell which would automatically get invoked.
your executable file here is /C" + "\"\"C:\\Program Files\\ThinTV\\PLINK.EXE and your arguments is appliance@%ThinConnectedFrom%" + " " + "-pw appliance" + " " + "\"killall -q vlc; export DISPLAY=.0; vlc --halfscreen --key-vol-up 100 rtsp://stfamtv0001/streama\"\""