AutoHotKey example: hotkey activated loop, skip if window not in focus.

hotkey-activated-loop.ahk

#Requires AutoHotkey v2.0
#SingleInstance Force
#MaxThreadsPerHotkey 2

windowTitle := "ahk_exe notepad.exe"

#HotIf WinActive(windowTitle)
+F1:: {
    static running := false
    running := !running
    TrayTip(running ? "Running" : "Stopped")
    SetTimer TimedLoop, running ? 1000 : 0
}


TimedLoop() {
    if (!WinActive(windowTitle)) {
        return
    }

    Send "{C down}"
    Send "{C up}"

    Send "{N down}"
    Send "{N up}"

    Send "{M down}"
    Send "{M up}"
}