Adding custom input fields

Hi everyone,

I’m looking for a forum / bulletin board plugin with the option to create custom input fields that appear on the site when creating a new topic, e.g. below the ‘Title’ input field. This input should also be displayed in the created topic.
I’ve tried to achieve this with bbPress, but without success – perhaps I was doing something wrong. The tutorial I followed wasn’t exactly clear. I also gave WP Symposium a try, but again, no option to create custom input fields. Is there another plugin that would let me do this? If not, what can I do to add these input fields myself? (I.e. modifying either bbPress or WP Symposium.)

Thanks for any suggestions!

Rosa