I guess you just need to specify absolute path for yii.php and main.php files.
So I think following lines should work fine.
$yii='C://wamp/www/yii-1.1.8.r3324/framework/yii.php';
$config='C://wamp/www/examapp/protected/config/main.php';
Also you can use dirname(__FILE__)
to get the current directory and set the path to files relatively from that directory, which would be better solution.