If I have an object like this on a specific website:
<div class="header">
    <h1>Welcome to the site</h1>
    <p>Foo bar baz spam</p>
</div>
Is there a way to make an element on my site display the content of the first div with that class?
For example, on https://stackoverflow.com, there's a div with the class "-container" near the top of the page.
<header class="top-bar js-top-bar _fixed">
    <div class="-container">
        <div class="-main">
                <a href="https://stackoverflow.com" class="-logo js-gps-track"
                   data-gps-track="top_nav.click({is_current:true, location:1, destination:8})">
                    <span class="-img _glyph">Stack Overflow</span>
                </a>
         <!-- More data follows -->
So, on my site, let's say I had a special element with a certain class that specified the website and class to pull from. The HTML would look like this:
<div class="mySpecialClass">
    <div class="-main">
                    <a href="https://stackoverflow.com" class="-logo js-gps-track"
                       data-gps-track="top_nav.click({is_current:true, location:1, destination:8})">
                        <span class="-img _glyph">Stack Overflow</span>
                    </a>
             <!-- More data follows -->
</div>
Is there a way to do this with HTML, CSS, PHP or similar?
