Added the regex_match Form Validation rule.  Had to change how the rules are split so that no regex breaks the rule splitting.
diff --git a/system/language/english/form_validation_lang.php b/system/language/english/form_validation_lang.php
index 99ed70a..b018850 100644
--- a/system/language/english/form_validation_lang.php
+++ b/system/language/english/form_validation_lang.php
@@ -15,6 +15,7 @@
 $lang['numeric']			= "The %s field must contain only numbers.";
 $lang['is_numeric']			= "The %s field must contain only numeric characters.";
 $lang['integer']			= "The %s field must contain an integer.";
+$lang['regex_match']		= "The %s field is not in the correct format.";
 $lang['matches']			= "The %s field does not match the %s field.";
 $lang['is_natural']			= "The %s field must contain only positive numbers.";
 $lang['is_natural_no_zero']	= "The %s field must contain a number greater than zero.";