The problem is: how do you want to identify the very object you want to edit?
A pointer is a memory address to a specific entity and thus you can edit that very entity.
A string with "box" inside is hard to translate to a specific entity.
Because how do you want to identify it?
By the filename? What about multiple instances of a file then?

You can use either the filename or you use a name which you attached to an entity using WED and use the command ent_for_name

You could also store the name in a skill or in string1/2.
Then you have to search the entity in the list of entities and then edit it.