The command window is not being delivered with HC12 or HC08 as we do not include debugger parts of the CW ide.
The simplest way to pick the right ide with COM is to call the bin\regserver.bat of the ide you want to control before you create the initial connection.
I think also launching CW and then using COM to connect to the currently running ide works, but you never know how long you have to wait until the ide is really up and running, so I prefer to let COM start the ide.
Notes:
regserver.bat supports /s as option, then it does not stay open.
Use the bin folder as current directory when launching regserver.bat, I think it is a bit limited in this respect.
Simple builds can also be done with CmdIDE.exe, it has some options to let you specify the mcp and the build target. However it is not an interactive shell, it just pipes through the output of the build process happening inside of CW.
Daniel