Applying Universal Email to your page will not change any of the form fields or their values. When you click finish it puts the php code onto your page that will send the email. When you configure UE you specify all of the properties of the email including the to, cc, bcc and other aspects. What you set in the wizard are the values that will be used to send the message.
If you are setting the to address in a text field in your form then you will need to edit your UE server behavior and update the to address, use the lightning bolt icon to selet the to text field in your form. With it setup like this when the server behavior is triggered it will send a message to the address specified in the to field, then it will also send emails to each entry in bcc that is coming directly from the db. Is this how you would like it to work? If not please describe how it should be working.