PHP标签内的PHP标签？

Question

So I just follow this guide:

http://www.bitrepository.com/php-how-to-add-multi-language-support-to-a-website.html

And everything is working but now I got in to a problem:

Everywhere that I want text I place: <?php echo $lang['FOOTER_CURRENCY']; ?>

But I have a php code for RSS feed: (right inside my php file)

<?php
    // Show number of items  
    $items = 6;  

    // Load rss into simplexml rss from pctuts http://www.pctuts.be/external.php?do=rss&type=newcontent&sectionid=1&days=120&count=10 just replace this link voor the right one
    $rss        = simplexml_load_file('http://test.blogspot.com/feeds/posts/default?alt=rss'); 

    // show last items  
    for($i=0;$i<$items;$i+=1)  
       {  
       echo "<div class=\"channel\"><a href=\"{$rss->channel->item[$i]->link}\" target=\"_blank\">{$rss->channel->item[$i]->title}</a></div>
";
       }  

    ?>

Now I wan't to replace the RSS Feed link with every language. So I replaced this like I usualy do:

This:

$rss        = simplexml_load_file('http://cupandsaucersweden.blogspot.nl/feeds/posts/default?alt=rss');

To:

$rss        = simplexml_load_file('<?php echo $lang['FOOTER_RSSFEED']; ?>');

Well ofcourse a php tag inside a php tag won't work so I did this:

$rss        = simplexml_load_file('echo $lang['FOOTER_RSSFEED']; ');

Doesn't work either, I tried many other things but it just won't work. Can someone help me with this?