all that happen is MC opens the MC folder
That is because MCC 20000 doesn't do what you're trying to do. Sorry, you got some bad advice above.
But first, relating to this:
so this is what I'm really trying to do,
http://192.168.1.83:52199/MCWS/v1/Control/MCC?Command=20000 H:\AllMedia\TV Shows\Angel\Season 1\Angel S1E1.mp4
Just to check, are you trying to open a file from the command line on the same computer that is going to actually play it? Or a different one across the network? You're probably just a bit confused, but... Assuming you're being normal and trying to use MC on the computer that you have in front of you, and not some other computer on the network somewhere, this is super simple.
Media Center's Command Line Options are documented here:
http://wiki.jriver.com/index.php/The_Command_LineThe Command Line interface has a bunch of stuff it can do on its own. But, it
also gives you access to all of the MC Core Commands (which are more "automation" commands). The Core Commands (MCCs) are documented here:
http://wiki.jriver.com/index.php/Media_Center_Core_CommandsBut, you don't need any core commands to play a file. There is a /play command part of the regular command line UI, which takes a <playitem> parameter that can be any file on disk (or Playlist in MC, or a bunch of other types of things).
The core commands aren't for stuff like that. They are for
automation ("emulating" things you could do in MC yourself with a keyboard shortcut or by clicking on things). The 20000 MCC you found does
the exact same thing as going to
File > Open Media File: it shows you the file browse dialog. Your extra parameter it doesn't understand is ignored. The MCC commands
never take strings and complex arguments. They
always take only integers, like this:
mc21.exe /mcc /MCC 23020,1That one runs the same thing as
Tools > Import > Run Auto Import Now, but does so silently (that's the ,1 after the 23020 command). They're like "secret toggles" you can command to "automate" what you would normally do in MC yourself with a mouse or keyboard.
So, you don't want that. You want the Play command. To do what you want in MC from the command line, using MC21, and assuming you're not trying to do it across the network on some other computer or anything crazy, you'd enter
mc21.exe /play "C:\path\to\file.flac"
or for a video:
mc21.exe /play "C:\path\to\file.mkv"
Which is directly from the documentation page in the Wiki (except I fixed it to be for mc21.exe).