Noob question about referencing objects


Righto, hopefully the last shreds of my noobism will be discarded with the answering of this question.

I have the following object:


It’s a placed object that upon first-run creates a tree:


Because there are a lot of trees, that number at the end is random.

My spawner object needs to continue to interact with that particular tree. How do I do this? What is the exact syntax I’d use to let the contents of a variable indicate the path to the object I want to alter? Or is there another way to reference it?