Now, I'm having a little bit of a hard time understanding what you mean, but then again it is a harder problem, so bear with me here.
What I'm getting here, and tell me in the comments if I'm wrong, is that you want your phone to "hear" that you touched the brick, without having actually interacting with the brick at all.
Rather, you want to modify the program so that you can touch a GUI button and the program will "hear" the touch event as broadcast by your phone, rather than by the brick.
This will be entirely program-based, and will not require any "hacking" of your brick. But it does mean that you will be required to make a new version of the program to include this function, the false touch, and that really depends on how good you are at programming ios, or whatever language your touchscreen device is based on.
I know this isn't completely as helpful as you might desire, but this might not be the best place to ask about programming, and programming is what it will come down to. We do have an SE site for that!