All of the URLs within UBB.threads are hardcoded, meaning it'd take modifying files to change were these locations are pointing to which will disable their internal functions within UBB.threads.

-- WARNING -- UBBCentral and UBBSystems do not provide support for modified forums, we cannot guarantee that your modifications were performed in a manner which wouldn't interfere with the base product as designed; as such, by modifying your support you're foregoing your ability to get official support.

That being said I'm assuming you're wanting to replace the location the "register" link (from the header) goes to, which would be taken care of by this kludge in /templates/default/header.tpl:
Code
{if $new_user_link}
<a href="{ubb url="ubb=newuser"}" class="nw" rel="nofollow"><i class="far fa-check-square fa-fw" aria-hidden="true"></i> {$lang.NEW_USER}</a>
{/if}

If you're actually wanting to modify the registration page you'll be looking at modifying the page: /templates/default/newuser_signup.tpl and its associated language file /languages/english/newuser.php

I am a Web Development Contractor, I do not work for UBBCentral. I have provided free User to User Support since the beginning of these support forums.
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