Yii1资产的完整路径

I am trying to figure out a way to upload files to a remote server using Yii and a custom component that curls the files to the server. However, i am getting an http_code 0 and i think this is due to the fact that i am trying to send

@/dirtoproject/assets/44d360bd/upload/images/stalker-cityscapes_00324219.jpg;filename=stalker-cityscapes_00324219.jpg;type=text/html

instead of:

@/pathfromc:/ /assets/44d360bd/upload/images/stalker-cityscapes_00324219.jpg;filename=stalker-cityscapes_00324219.jpg;type=text/html

Can anyone explain my how i can get my path right? I am using

protected function getKCFinderUrl()
{
    if ($this->_kcassetsUrl === null)
        $this->_kcassetsUrl = Yii::app()->getAssetManager()->publish(
            Yii::getPathOfAlias('ext.kcfinder') );
    return $this->_kcassetsUrl;
}

to load the kcfinder extension. all help will be appreciated.

Adding $_SERVER['document_root'] works just fine.