I’d suggest making an EE template just with the output that you want and then using file_get_contents() to pull it into your other php page. Your ee template could be something like
<ul>
{exp:weblog:entries weblog="my_weblog" disable="custom_fields|categories|category_fields|member_data|pagination|trackbacks" dynamic="off" limit="5"}
{if no_results}
<li>No Results</li>
{/if}
<li><a href="http://{path=blog/comments">{title}</a></li>
{/exp:weblog:entries}
</ul>
and your PHP file could have something like this in it
<h3>Latest News Headlines</h3>
<p><? echo file_get_contents("http://mysite.com/blog/latest_headlines/");?>
The file_get_contents function stores the contents in a string in PHP. You can read about it here: PHP:// file_get_contents