Lower shoulder buttons use the xbox360 controller to switch missiles in Metroid: Samus Returns

Hello everybody. I like to play Metroid: Samus Returns.
I have an i7 4790 Pc and the Citra Emulator is really good with me.
I use an Xbox360 controller to play. My question now; Metroid has no key on the Xbox Controller, so you can switch from the missile to the Super Missile. You have to switch this from the lower screen, so hold down R and then select the Super Missile icon. In that case with me at the emulator I must do this with my PC mouse. That’s pretty annoying when it has to be done quickly. Is there a programming that you can use the symbols in the game with the rest of the controller buttons from the Xbox360 controller. Because the lower shoulder buttons and the right round stick are not used, for example. It would be great if someone could program the Touch Pad function so that Metroid: Samus Returns could, for example, serve the lower shoulder buttons to switch the missiles.
I’m from Germany, I used the Google translator, my english is not that good. Thank you first

There’s no official support for mapping the touch screen to a controller though I can see why it would be useful. For that you’ll have to use a third party software, maybe AutoHotkey, to map the mouse click in a specific region of the screen to the controller.

Thank you for the fast answer. are there videos about these tools like autohotkey? I generally have not the idea of what name I would have to enter on the internet, maybe I’m the only one who asks for such a function

I’ve never used AutoHotkey but you can try asking about this in their forum.