Trying to query for categories and display archive pages in a protected plugin

I'm a "hunt and peck" PHP person - I really don't know that much about PHP, and generally just try to find examples that do what I want, and copy them. Sorry :slight_smile:

I am trying to edit a plugin that I purchased for another membership site that is locked down pretty tightly (this is not the WPMU Membership plugin).

If you are not logged in, you only have access to certain pages, and have no access to blog posts. I would like to give access to blog posts. My thought is that if I can make a query that will check for a category and return the archive page for that category regardless of whether logged in, that would work. So, I know that I'm close, because instead of getting a "you don't have access to this content" when trying to get to my "welcome" category, I get a blank page. I'm sure it's just that I have no idea what I'm supposed to "return" for the archive page. Here's what I've added:

if (is category ("welcome"))return '/archive.php';

I've also tried to "return $template" - my guess is that "return" might not be what I want. In any event, I would like for any posts in a couple of categories to be visible to all visitors. I know that once I get the context right, I can add an array for the categories, so I really just need to get one of them working.