Can you not use the Web or Mail Link section of the Site Info panel of the Web Module?
I tried and could not get it to work no errors just a blank field. But do use the mailto to allow clients to email me with the images they want - so having both the mail function and the home page link is what I need.
I am guessing as I am not an XML programmer - but I am guessing you could use those fields but would require additional code outside of Lightroom or Bridge - so I took the easy way out.
If there are some XML guru's out there that would like to put something together then I am all ears. Microsoft provides and XML editor so adding the code to this file would be a copy and paste.