Which plugin for a simple, well-designed, form/survey plugin?

Hi,
I’m looking for a way (maybe a plugin) that allow selected users to fill a brief form.
These selected users are teachers that are participating to a no-profit project about teaching CPR, I need to allow them to upload how many student they have reached with this project (they should upload date and number of participants for every lesson) and I like to have a way to export a .csv with their answers.

I’m not an hacker (I’m a MD) and I’d like to have a week designed simple plugin.

Thanks for your help!

Enrico