php - How add external controller to ZEND module

Question

I want make a in my CMS autoload plugin, which will be automaticly load externall controller to my admin module.

I writing because I have problem with add external controller to my Zend module. My situation is: I have Admin module and external catalog: ROOT_PATH |-modules |-ModProducts |-controller |-forms |-models |-DbTable |-views

Zend give me instruction addControllerDirectory but When use this instruction:

$frontController = Zend_Controller_Front::getInstance();

    $frontController->addControllerDirectory(
        ROOT_PATH . '/modules/mod_products/controllers','admin'
        );
    $frontController->addControllerDirectory(
        APPLICATION_PATH . '/modules/admin/controllers','admin'
        );

Module Products not working. I get error: " Invalid controller specified (Module-Products)"

When i change line in the code: $frontController = Zend_Controller_Front::getInstance();

    $frontController->addControllerDirectory(
        APPLICATION_PATH . '/modules/admin/controllers','admin'
        );

    $frontController->addControllerDirectory(
        ROOT_PATH . '/modules/mod_products/controllers','admin'
        );

My Admin module is not working and I get this same errror.

I know how load resources (forms, models etc.) but i don't know how load external controller.

Please helpe me.