Thanks, that's the perfect command.
Do you see why this doesn't work?
#2::
Run, C:\Windows\System32\notepad.exe, , , notepad1pid
Run, C:\Windows\System32\notepad.exe, , , notepad2pid
Sleep, 500
ControlSend, notepad1pid, Hello Notepad 1
ControlSend, notepad2pid, Hello Notepad 2
return