I'm trying to use the Contact Form 7 plugin for Wordpress for a local hotel that is owned by a large national chain (Choice Hotels).
Choice Hotels redirects all bookings to their website but we want to build a form that lives on this individual website and then performs a search for the given arrive date, depart date, # of rooms, # of adults, and # of children.
This "Easy Booker" is an example of the functionality that we want (not the design though, that's handled by Contact Form 7 in the theme we're using) http://www.comfortinnalbany.com/
Do I need to use a PHP script? Can I do anything inside Contact Form 7 itself?
You could do just what Easy Booker does: include the parameters in the URL.
Hack the form action in Contact Form 7 so it adds the search vars to the string,
Then you can grab and use the vars in the page that receives the form.
See Get the GET variables from a URL String