Item Creation - Code to make it do what I would like?

[shartahl]

There will be an item that gives 5 temp HP. Each round, these temp hit point regenerate at a rate of two, but can't go above 5. Is there a way to automate this with an effect line of code? I know the loop logic in general with some if-then checks, but don't know how to do it in this

[LordEntrails]

Nope. Effects do not support the type of logic this would need.

You could create a custom extension that provides such logic.