Need help creating a custom portal

[Guest]

I know how to make door portals just fine, but what I want is to create a portal that uses any item as a trigger, for example a crystal or a pillar. I've tried a bit by making my own activator and adding some portal scripts, then choosing my cell in properties, but it can't be triggered in the game, as in there is no text when you put the crosshair over it. What items can I use and how do I set up the script? If you can point to an example where it's done it would help.