Dunno if you still need this answer but for future reference (and in case others find this page) here are the commands for changing screen:
Project flyout- %windir%\System32\DisplaySwitch.exe
PC screen only- %windir%\System32\DisplaySwitch.exe /internal
Duplicate- %windir%\System32\DisplaySwitch.exe /clone
Extend- %windir%\System32\DisplaySwitch.exe /extend
Second screen only- %windir%\System32\DisplaySwitch.exe /external