c++ – How to allow infinite custom inputs?

Summary: What approach should I take to allow custom inputs saved in a file be interpreted in the engine?

So I am making a game engine similar to Mugen where I want characters to have their own special combo inputs. Similar to how Kage has the Shun Goku Satsu. Where its just a combination of multiple keys pressed in quick succession. The thing is I want to give the ability to create these combinations to the character creators and let the engine handle the rest.

I already parsed the list of moves from the character file, so now I got an in-memory list of valid input sequences for each character and what moves they trigger. But I don’t really know how to interpret a valid sequence.