This is not possible. Apple would never allow such a huge security risk.
You misunderstand how Seetest works. Seetest requires access to your App's binary code, which it instruments:
https://docs.experitest.com/display/public/UFT/iOS+Applications
It then simulates user events by calling event handling methods, e.g. @IBAction
handlers. It does not go to the low level that you want, because nothing can unless you violate Apple's usage rules.
EDIT
I was assuming you wanted to write an iOS App that could generate events outside of its sandbox. Instead I think you're referring to Instruments which is controlled by a host.
Because this is a general question, see if this gets you in the right direction:
https://developer.apple.com/library/ios/documentation/DeveloperTools/Conceptual/InstrumentsUserGuide/UsingtheAutomationInstrument/UsingtheAutomationInstrument.html