Change some form fields values before saving valid form

Hi, I need to use the “wpcf7_before_send_mail” hook to change some field values, then save them so that the changes are reflected in the tags in the body of the sent email, including the tags used in the Send PDF for Contact Form 7 plugin, which I use to generate form fields to PDF as an attachment email. And at the same time show these changed field values in the Flamingo plugin.

Unfortunately, I cannot use the “wpcf7_posted_data” hook to change the values, as I use the generated formatted number autoincrement for one field, which I cannot “waste” this number if the form is not valid, which is ensured only by the “wpcf7_before_send_mail” hook.

Is there any solution to this situation? Please send me example.

Thank you very much for any help.

Have a nice day
Michal