Hi 678GUY,
I’m a bit confused. Do you mean how do you check on an event if the Right Mouse Button is pressed?
If so, what I would do is create a boolean variable that is set to true when the button is pressed and false when released, then you simply check if the boolean is true during the alternative event. For example, if you wanted an alternate fire on the LMB that only occurs if RMB is held down, it checks to see if the RMB boolean is true, if so, use the alternate fire, if false, use the primary fire.