PHP在第一次连接时改变HTML

Currently I have a php-page using include to show an html-page.

What I want to do is use a variable the php-page received when being called and project data into a field of the html-page depending on this variable. The problem is that I can't seem to pass the variable from php to html without using html to call php.

I know that I can simply echo the php-part, but because I can't echo straight into one of the html-page's divs it ends up putting the echo at the beginning or end of the page.

What I want to accomplish is for the html-page to load the php-part into one of the div's the first time the php includes the html-page. Is there any way to do such a thing?

If this isn't possible, then how do I get the javascript in the html-page to use the variable from the php-file? Is the best option really the href?

As requested some of the code: php:

if (filter_input(INPUT_GET, "event", FILTER_SANITIZE_STRING))
{
  include "../Html/EventPage.html"; //target page
  $temp = filter_input(INPUT_GET, "event", FILTER_SANITIZE_STRING); //get the variable
  include "../PHP/Connector.php"; //include the connection page
  $value = callFunction(Connect(), $temp); //call connection page and return value
  echo "<div class = 'cant select div in html'>" . $value . "</div>"; //echo value in location 
}

html:

<div id = "dynamic">
   this should have the php
</div>

I assume you use some code like this to display the page:

include('page.html');

A safer way would be to prevent evaluation in page.html:

echo file_get_contents('page.html', true);

You can then do any string modification you want for the content:

$replacement = 'MY REPLACEMENT';
echo str_replace('<div id="my-div">', '<div id="my-div">' . $replacement, file_get_contents('page.html', true));