Pugin for Dynamic Email Address Based on User Zip Code

Hello, I’m looking for a plugin or some solution that will allow users to dynamically send an email via a form to various recipients based on the user’s zip code (recipient depends on user’s zip). I’m thinking all that would really be required would be that the user enter their name and zip as fields, and the plugin/solution would dynamically look up the appropriate recipient based on zip code, populate the body of the email with the pre-written text and the user’s name, and send to the proper recipient.

I was told Gravity Forms is a powerful plugin for forms like this, but it’s not free. I was looking at using Contact Form 7 but it doesn’t seem to have this ability. Also, I have a custom theme with WordPress 3.3.2, I can’t update WP without losing changes to the site, and Gravity Forms requires v. 3.5 or higher. So not sure what the best option would be.

Any thoughts? Thanks!