Pinpoint Booking System - Only one Password for Member's Reservation

Hello everyone,

I’m creating a website for a sports club. This sports club has two halls that can be booked. There are two types of people booking these halls: Members who pay a yearly fee and customers who book just an hour. I’ve made a calendar with Pinpoint Booking System for each of the halls. Members who pay a yearly fee should be able to book directly in this calendar, while other customers have to make reservations via phone. To make it easy for the members, they shouldn’t be forced to register and instead just get a password, the same password for all.

I’ve edited the form for the calendars and added the password as allowed characters. Let’s say the Password is 1234. The problem is with the allowed characters, that things like 1333 or 4444 or 4432 are allowed, too, this way.

Is there any code to add to the allowed characters that would only allow 1234 and no other combinations of these characters?