displaying variable within html markup

I am trying to modify a video lightbox plugin. I want to display some text in the div with the pp_left class that will vary depending on which video is being played.

add_action('wp_footer', 'wp_vid_footer_content');
function wp_vid_footer_content()
{wp_vid_lightbox_style();}

function wp_vid_lightbox_style()
{
$description="something" //is there where i define $description??
$vid_lightbox_markup	  = '<div class="pp_pic_holder"> \
<div class="pp_left"><p>I want my variable to display here. What is the proper syntax??.' echo $description'. </p>
</div> \ ...etc

Any help would be appreciated.