Split and replace things with PHP and preg_replace

I have a PHP + HTML code as a string containing functions. I want some function calls to be replaced with included content. Put together many files to one.

Short example - Before

<html>
    <?php myclass->my_function('one', 'two', 'three'); ?>
    <h1>Content in between</h1>
    <?php myclass->my_function('1', '2'); ?>
</html>

Short example - Replacing content

<html>
    <?php run('one', 'two', 'three'); /* Run does include a file */ ?>
    <h1>Content in between</h1>
    <?php run('1', '2'); /* Run does include a file */ ?>
</html>`

Short example - After

<html>
    <?php
    /* Start my_function */
        echo 'This is the result of my_function one two three';
    /* End my_function
    ?>
    <h1>Content in between</h1>
    <?php
    /* Start my_function */
        <?php myclass->my_function('four', 'five', 'six'); ?>
    /* End my_function
    ?>
</html>

Notice that myclass is found in the included content. The result needs to be parsed again.

Short example - After that

The whole this is parsed again and it replaced the myclass with included content.

<html>
    <?php
    /* Start my_function */
        echo 'This is the result of my_function one two three';
    /* End my_function */
    ?>
    <h1>Content in between</h1>
    <?php
    /* Start my_function */
        echo 'four five six';
    /* End my_function */
    ?>
</html>

I tried to do this with explode but it went to complex. The two steps "Replacing content" and "After" might need to be done in one move.

Look at it as a string. Can preg_replace solve this? How?

$str = '<html>
<?php myclass->my_function(\'styles\', \'home.css\'); ?>
<p>Some other content</p>
<?php myclass->my_function(1, 2, 3); ?>
</html>';

function jens($matches)
{ 
    $path = '';
    $parts = explode(',', $matches[1]);
    foreach($parts as $match)
        $path .= '/' . str_replace('\'', '', trim($match));

    return $path;
}

$replaced = preg_replace_callback('/<\?php myclass->my_function\((.*?)\); \?>/', 'jens', $str);

echo $replaced;

Should do what you want.