Hi bpierce,
If you’re comfortable with working with JavaScript, you can try using Axure Share’s “plugins” feature. Axure Share plugins allow you to include custom HTML, CSS, or JS into your published prototypes, so you may be able to add the specific JavaScript code that does this through a plugin. If you’re interested in giving this a try, I’d recommend checking out the support page here as well as this forum post:
Hopefully this helps! Keep in mind that while we may be able to assist with the plugin setup process, we won’t be able to provide support or troubleshooting for the code you’re adding in via the plugins.