I might have an idea. It is a long shot, but you can give it a try.
What you can do is add a dummy device for every input of the switch point(something you don't actually have) and assign to this device for the power on button the corresponding ir code of the switch box input. Add this device to the activity. And when you switch on the activity is also switches the dummy on, therefore it sends the ir code to the switch box.
One thing you have to solve still. That is if you switch from one activity to another the switch box is not controlled. This can (I think) be circumvented by choosing the right dummy device which also has an assignment for a input selection and program the ir code for the input selection as well
I know this is not a elegant method, because your screens will expanded with buttons you don't need and it maybe don't even work.