Template hooks
 

How can I edit a template from a plugin using a template hook? Is that possible?

Have you tried reading any articles about this?

Cellarius wrote a really good article that you may be interested in - [vB4] Rendering templates and registering variables - a short guide

I've tried finding some tutorials on this, I don't think that's what I'm looking for. I'm trying to basically insert my variable into a template from a plugin because there's no hook spots for where I need it

You will need to register that variable for use in the template and that is what that article is about.

Yes, but I don't want to manually add the variable to the template.. I want to somehow find a way to insert it with a plugin.

You may be able to do a str_replace then.

http://php.net/manual/en/function.str-replace.php

I've tried that, but I'm stuck on actually how I'm supposed to read the template

I would suggest posting exactly what you have done (please use code tags), letting us see the result, and then we can help you out. Right now, you are being way to general for us to be of any help.

I know the hook is wrong because they don't read it actually, which is what I'm needing to figure out how to do.

What plugin hook are you using?