Temporary magnetic switch?

I'm trying to create a switch where I can have a magnet strike a steel plate that will signal a counter then reset for another signal. I have very basic electronics know how and have yielded no luck other than a reed switch from google. Effectively I am trying to achieve a counter to set off a buzzer once a certain number of strikes are reached while the magnets stay in place. It's not pertinent to have the magnet remain as long as the hit is calculated. Thanks in advance.