Pls check the file contact-shortcodes.php in {theme directory}/framework/shortcodes/ folder (and sendmail.php in the /scripts/ folder if you need to).
You may have trouble with changing URL validation behaviour since it is handled validate JS. You can download the source from
http://jqueryvalidation.org/validate/
link the theme to it, and change the JS file if you really need to. Let me know if you need further help on this. Thanks