Direct a permalink to another page

It sounds like your plugin is in control of the link. Perhaps you should ask in the plugin support forum.

Thanks for the reply. They don’t seem to be that good on their support unfortunately.

Are you aware of any other way of doing a redirect with a permalink without htaccess?

To modify what is requested of the server when a link is clicked, you use .htaccess.
To interpret the URL that WordPress is given to process, you use rewrite rules, in code.
Yes, the .htaccess file can have Redirects and Rewrites, but that all happens before WordPress sees it. WordPress can do internal redirects also, based on changes to your permalink (it saves _wp_old_slug as a post meta field), but your plugin is doing its own thing, so it’s not a straight-forward situation.

The proper way to alter what your plugin does with permalinks is find out what it does in code and have your own code alter that in code that runs later. Determining what a plugin does about a specific thing can be difficult. A hacky alternative is find the applicable rewrite rules in options and alter the query vars created by the rules to do what you want. Again, finding the applicable rules can be difficult unless you are very fluent in regexp.

You say you want the image permalinks to reload the current page instead of going to the specific image page? If so, why have links at all? That sort of action can likely confuse many users and cause them to think your page is broken. Maybe you should be finding a way in the plugin to not have links at all.