I am thinking about adding a feature to mark snippets of html as macros (Like Velocity macros) but this isn't complete yet. Right now all you can do is including parts of html.
Example:
<!--$include b.html @ /html/body/div -->
The statement above will include the first div inside the body tag of the b.html file. So as you can see in this example, you don't have to include a whole file, but you can include just parts of it.
I haven't tried this, but you can try including certain parts of the same page to do what you want to do. Another option is creating a template with reusable sets of html snippets and including them in other template files. If you add an id to your tags that you want to reuse and include them like this:
<!--$include snippets.html @ #foo -->
Thanks,
Erdinc