How to add a non-user CP field in registration form to collect data BUT...

[timetunnel]

Hello.

How do I add a field in the registration form that doesn't show up in 'User CP but is added to the database for analysis reporting, later?

I would like to collect data e.g. on how the visitor learned about the site e.g. a dropdown box with a list of names of search engines plus 'other' whereby 'other' can be elaborated in an accompanying text field (e.g. they can add the member's name or other source like print ad name, etc.). I'd like this data added to the database for later compilation.

I prefer not to dismantal the built-in referrer system.

Thanks in advance.