Simple Android App - Dial One When Call Taken

Hi, I need a simple android app made. I want the app to automatically dial 1 when a call is received and answered. It should be immediately upon answering the call. This is to be used by my IVR system, which needs to detect a 1 pressed. Should not require rooting. That's it. Alternatively, if you know of a tasker that would do this task without rooting, that works too.