faidon said:
1. prepare a letter ( a wp post) addressed to an organization/individual (email address is provided by me and it is either displayed or witheld in the email form field)
can't do. you need to confifure cforms input/message fields directly.
2. have users that are registered to my website read it and at the end of it include one comment.
the comment could be a simple multi line text field
Not registerd user should register first.
you need to control via PHP what visitor/user gets to see and use the form/page.
3. add a box below that with their name/signature
single line text field or e.g. image upload (scanned signature).
4. have them send this letter i.e full post content) - (to the email address as per the email form field incorporating their comment, name and sig., subject to web-admin approval
you can control the admin email address several ways. multi recipients, change it based on custom logic in my-functions.php
6 copy to sender and the website (my website)
CC & BCC option