向视图添加单个按钮

I've setup a view in drupal that lists items like this:

IMAGE 1 | IMAGE 2 | IMAGE 3 | IMAGE 4
 desc   |  desc   |   desc  |  desc

I'd like to add a single button to the top of this view. I would prefer to do it with code or a module, without digging into the theme templates. But how?

You can add the code in the header of the view (it's under "Basic settings" in the views configuration page).