On the forum you surround the "img" tags with "url" tags like this:
[URL=http://www.your-website.com][img]http://www.your-website.com/wxgraphic/wxgraphic.php?type=banner[/img][/URL]
If it's HTML code you want so that visitors can use your wxgraphics on the their own website then it looks like this:
<a href="http://www.your-website.com"><img src="http://www.your-website.com/wxgraphic/wxgraphic.php?type=banner_stones" alt="your-website.com" border="0" /></a>