Add new user data to External Database

I am trying to figure out to add my own function to insert the customer data into an external database at the time of registration. I am currently using the custom form and fields created by s2member. I currently have my code in near this block inside of the wp-login.php. It seems that the custom registration doesn’t use this block of code.

$user_pass = wp_generate_password( 12, false);
	$user_id = wp_create_user( $sanitized_user_login, $user_pass, $user_email );
	if ( ! $user_id ) {
		$errors-&gt;add( 'registerfail', sprintf( __( '<strong>ERROR</strong>: Couldn&#8217;t register you... please contact the <a href="mailto:%s">webmaster</a> !' ), get_option( 'admin_email' ) ) );
		return $errors;
	} 
	//MY CODE
	else {
		include('wp-content/themes/Sterling/include/phpFunctions.php');
		msc_add_user($user_id, $sanitized_user_login, $user_email);
	}