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