You could add a field to the form and add the content of the REQUEST variable after submitting to the message text.
That requires one additional field in the form, a getParam line at the beginning of public.php and one line in the save message function.
Sorry, since this is a very special hack I cannot provide further support for that since I have no spare time for individual changes.
uddeIM & uddePF Development
CB Language Workgroup
CB 3rd Party Developer