item count in sharepoint

Hello Techies,

I have a Event list and Registration list

Event list contains all upcoming events and registration list consists of all registration with respect to events

Note : Event title is lookup column in registration list

Registration list has one column in register with yes/no radio button.

based on registration (yes) i need to count of number of users registered for that particular event in Event List.

Problem : Since i used event title as lookup in registration list i was able to take the loopkup of eventTitle column registration list which returns count of number of items in registration list created using that event .

But i need the count of items with status YES in Event List.

Any help will be appreciated