The way I've accomplished something like that in the past (and it kind of depends what you want to do) is something like this. Say you want something to happen when the player is in the space of x = 5~7, and y = 5~7.
Here the forest represents the space you want the event to occur in. Next, the two empty graphic events in the corner there.
Next, set up variables that can track the player's X and Y coordinates on the map (also useful for other times you want to track the player's position, and not just this event), set as a parallel process.
Last, I made another parallel process with the event I wanted to happen. In this case, I have a bell continuously sound whenever the player is standing in the woods. This could be more complicated as well.
Be sure in those empty graphic events if you think anything else might be passing by and have its movement blocked, make sure you check "through" so they don't stand in the way of any game choreography you might have.
It may not be exact way you want to do it in all situations, but I find this method useful.