Man after much trial and error (could find nearly sweet FA easy to understand guides)
I have managed to get this to work with the following AHK script
Script to force Intro Video To left Screen
Run "F:\Emulators\LaunchBox\bigbox.exe"
sleep, 2000
SetTitleMatchMode, 2
WinActivate Startup.mp4
Send {Esc}
Send #{Left 3}
sleep, 1000
Send {f}
With line breakdown
Runs my Big box install
Waits 2 seconds (for VLC to load)
Sets Title Match Mode of AHK to 2 meaning A window's title can contain WinTitle anywhere inside it to be a match
Tells AHK what to look for in the windows title
Press ESC to force VLC out of fullscreen
Press Windows button + left arrow key 3 times (To ensure it is on the left screen)
Wait 1 second as sending the next cmd too quickly would bug
Press F to maximise VLC
Once I had sorted that I decided to add PCSX2 (which also does not have a screen selection option)
SO I AHKED THAT AS WELL
added the following to ahk settings in launchbox emulation screen bit more basic as PCSX2 forces its emulation screen to be the active window (Which vlc doesn't)
Script to force PCSX2 to left screen
sleep, 4000
Send !{Enter}
Send #{Left 3}
Send !{Enter}
breakdown again
Wait 4 seconds
Alt+Enter exit fullscreen
Windows button + Left Arrow three times
Alt+Enter again for full screen
I know there is probably a more advance way to get it to work but forcing key inputs seemed the quickest and easiest to get working.
Edit - Spelling yey for dyslexia.