Referring to segment value without array syntax?

[tparvi]

Is there a way to set a segment value without using multiple array syntax like this:

tmp['PID']['PID.4']['PID.4.1'] = "value";

The reason I'm asking is because I want to use external json file to configure where certain values are written. The json file could have something like this (I made up the syntax):

lastName : "PID.PID.4.PID.4.1"

This means lastName should be written into that segment and then in code I could just write:

tmp[settings.lastName] = value;

Is there simple way to achieve this?