Thank you, Egg.

I've got your code working in the W3Schools try it window, by modifying it as follows. The question now is: how do I implement this within Xara WD?

Code:
<!DOCTYPE html>
<html>
<head>
<style>
body { 
background-image: url('http://parkeston.com/images/background-image.jpg');
background-repeat: no-repeat;
background-attachment: fixed;
background-position: right bottom; 
background-size: contain;
}
</style>
</head>
<body>

<h1>The background-position Property</h1>


</body>
</html>