I wrote the code and tested it; now all I need to do is figure out how to make a custom template.

Thanks

All you need to do is to copy the view.php from the /concrete/blocks/content folder out to the /application/blocks/content/templates/template_name.php here is a link to more information -http://documentation.concrete5.org/developers/working-with-blocks/w... if you don't want to put your custom CSS into the view.php file you can instead make the custom template like /application/blocks/content/templates/template_name/view.php and also put a view.css in that directory and it will load with the block on the page.

I'm tinkering with this at the moment. The key CSS is 'overflow:auto' or appropriate variants of that. Obviously you'll also need to specify the size of the relevant containers (probably DIVs). I'm using it in conjunction with "position:fixed" to get sidebar menus that don't scroll away when the main content is scrolled. It's basically working, but getting it to play nicely with built-in styles and templates will be a challenge.