on the admin_cms/users_login.php page, the following code performs the redirect:
<?php if(WA_Auth_RulePasses("Super Administrator")){ // Begin Show Region ?>
<?php header('Location: '.(isset($_GET['accesscheck'])?$_GET['accesscheck']:"index.php")); ?>
<?php } // End Show Region ?>
<?php if(WA_Auth_RulePasses("Administrator")){ // Begin Show Region ?>
<?php header('Location: index.php'); ?>
<?php } // End Show Region ?>