Custom programming for WP The Events Calendar

We have a Word Press site that uses the free version of The Events Calendar. We are looking for a custom program so only people with a generic password (1234) can see one of the event categories. We do not want a separate calendar, we just want one of the event categories to not be able to be seen on the main calendar without inputting a generic password. We also would like the categories to show on the main calendar page without having to upgrade to the paid version of this plug in. (if that is possible with custom programming)