I don't know if this is an acceptable solution (I don't claim to be a programmer) but you can create a hyperlink over the site logo by doing the following.
To link the site logo, I inserted a table with 2 cells in the Demo Banner. The table is set for 100% width. In the RIGHT cell enter what ever banner code you want. The LEFT cell will cover your site logo. Create a transparent gif and upload it to your template/images folder. Reference the transparent gif in the LEFT cell and link it to your url. Below is an example of the html for this
I have removed my own banner code, enter your own details.
I am in the early stages of editing this template and so if you check this latter I may have already changed it. For now however you can see it working at http://www.liftforlife.com/content/
(if this link doesn't work, type it in manually (doesn't seem to work from this post
I apologize in advance if the code sucks.