[Plugin: NextGen Gallery] Creating template using sidebar and innerHTML/iframe

Hi,

I’m relatively new to WP/Javascript. I’m trying to create a template page so I can display the links to the galleries in a sidebar and have them come up on the right in a separate div. Here’s basically what I want it to look like:
https://box453.bluehost.com:2083/viewer/home4%2fcaitlint%2fpublic_html/Picture%208.png

I feel like I’ve got the layout structure down based on what I’ve built so far:
>https://www.caitlintighe.com/work-2/
but I’m stuck on how to create the layout. Back in the old days, I would do some sort of frame layout with targets, but obviously that’s ancient history. So what would work with NextGen? Javascript innerHTML or an <iframe> or what? Any help is greatly appreciated. I’ve spent countless hours on research and am thoroughly exhausted and confused.