Change combination to open RetroArch settings menu in game?

Im using the 'My Arcade NES Mini Wireless Controller' and those controllers have the 'reset' function on Select + Start built in. Is there any way to change the combination to open RetroArch in game?

[pcm720]

Launch RetroArch, go to Settings -> Input and change Menu Toggle Gamepad Combo

Thanks, but none of the combinations of buttons that I can chose from is present on my two button controller. Is there any chance that the combination DOWN + START can be added?

[pcm720]

I doubt that this can be done without changing the source code and recompiling RetroArch.

[Bumblecito]

Maybe You can do it changing the the combination in RetroArch .cfg configuration file.
Here's a tut (sorry just found it in Spanish): https://www.youtube.com/watch?v=S58jedkaKTE