Contact Forms 7 limit mails accoriding to stock

Hello all,

I need some help…
In the netherlands museum can be open for the public but not more than 30 visitors a day(corona measures). Later 100 (July ?).
They are only open on Saturday and Sunday.
I Need a registration form where the visitor can select a date, set number of visitors, name and email.
Every saturday and sunday has a “stock” of 30 visitors. Every time a contactform/regsitration form is sent than the 30 has to be 30 minus the number of visitors in that form.
Example: Saturday 6th of June: 30 visitors availbale. Visitors fill in online form for 2 persons. Visitor and Museum get a confirmation mail with the title “6th of June, 2 persons” and important: the “stock” for this day is now 28.
Can that be done with CF7? Or with an add-on plugin ? Or code in child theme ? Or maybe even…. is there a better way? (no woocommerce)

Kind regards,
Marco