Can I user function.php overwritten some codes on wp-login.php?

Hi,
I want to overwritten

<?php
login_footer(‘user_pass’);
break;

case ‘register’ :
if ( is_multisite() ) {
// Multisite uses wp-signup.php
wp_redirect( apply_filters( ‘wp_signup_location’, site_url(‘wp-signup.php’) ) );
exit;
}

if ( !get_option(‘users_can_register’) ) {
wp_redirect( site_url(‘wp-login.php?registration=disabled’) );
exit();
}

$user_login = ”;
$user_email = ”;
if ( $http_post ) {
$user_login = $_POST[‘user_login’];
$user_email = $_POST[‘user_email’];
$errors = register_new_user($user_login, $user_email);
if ( !is_wp_error($errors) ) {
$redirect_to = !empty( $_POST[‘redirect_to’] ) ? $_POST[‘redirect_to’] : ‘wp-login.php?checkemail=registered‘;
wp_safe_redirect( $redirect_to );
exit();
}
}

$redirect_to = apply_filters( ‘registration_redirect’, !empty( $_REQUEST[‘redirect_to’] ) ? $_REQUEST[‘redirect_to’] : ” );
login_header(__(‘Registration Form’), ‘<p class=”message register”>’ . __(‘Register For This Site’) . ‘</p>’, $errors);
?>

‘wp-login.php?checkemail=registered
This code to bloginfo(‘url’) then if I click the register button it would direct to my homepage not the logi form.

Could any guys help me and I would appreciate.