//Prior ZF 1.8

$frontController->setControllerDirectory(array(
    'default'   => ROOT_PATH . '/application/controllers',
    'admin'     => ROOT_PATH . '/application/admin/controllers',
    'reports'   => ROOT_PATH . '/application/reports/controllers',
));

//How do you convert above code to fit into ZF 1.8 Zend_Application

I am able to set the controller directory for the default module. How do you specify the controller directory for other modules?