Access reply-to header in functions.php

Hi all

In the functions.php I can access to the email receiver and overwrite it, like this:

$mailProp = $contact_form->get_properties(‘mail’);
$mailProp[‘mail’][‘recipient’] = $recipient_email;
$contact_form->set_properties(array(‘mail’ => $mailProp[‘mail’]));

is it also possible, to overwrite header data, i.e. the reply-to in functions.php?

Thanks very much.