To put it as plain as possible, I'm trying to tell you to use the bindings tab.
When you add Universal Email to the page, you need to go to the body tab to crate the email message that will be sent.
On the body tab, select HTMLEmail and click the DW Edit button.
This will open a new page in Dreamweaver for you to crate the email message. It will have an editable region which will look like a blue box.
Inside of this blue box, you can design your email.
You can add text, table images (as long as you use a fully qualified URL).
You can also add the Form output.
To add the form output, go to the bindings panel and expand the form collection.
Select the form element you wish to output it and drag it to the page.
You previously said:
So if, as I understand your reply, I use UE to create the form, 
This is not the case.
you are not using UE to create the form, you are using UE to output the form in an email message.
When you create form, you add form elements like a text box:
<input name="textbox" type="text" id="textbox" />
this is what form builder does. it creates the form elements.
In the email message, you want to show what the user typed into the text box.
By using the forms binding panel when creating the email message, you add the code necessary to show that out:
<?php echo((isset($_POST["textbox"]))?$_POST["textbox"]:"") ?>
