Actually, I think you mis-understood slightly.
I don't think so - I think I understood you perfectly well.
All I wanted was for it to be on the registration page
Sure, the input field only needs to be on the registration page. But the salt (the secret, one-time, per user registration password) needs to be stored somewhere - the database. You need code to check the user input against that database field. And you need a page to enter the salt into the database, which probably would have to be an admin page. A lot of coding effort if you ask me, and all of that just for the purpose to get a correlation between your other app's user base and the one from coppermine - that's overkill.
Why don't you do as suggested and consider bridging? It would be exactly the solution you need. Alternatively, you'd need a routine that looped through your other app and created all accounts that exist in that app in coppermine as well; that would be the second best option.
As for links, well it's a private site so its not my place to decide to put a link to it.
Well, another "private" site on the internet? Yet another "security by obscurity" candidate? Anything site on the www is public. Privacy is achieved by authentification on the site and not by keeping the URL a secret.
Anyway, if you can't post it, that's a pity - you can't get support in that case.
As for the Coppermine site, it is a brand new installation so I can't see it doing much good.
You don't need to see that. It's
us who need to see something. It's our decision who we grant support and what we require as a prerequisite. You'd be suprised what we can find when looking at a fresh install. I'm not ready to explain to you why we need the link to your gallery.