Support for RPN-style variables?

[mamccollum]

This is a request related to more of an "extension" to RPN, but I've heard of there being some(?) calculators that support RPN-style variables; i.e. rather than doing q = 2, there is 2 then @q to store the value of 2 (the top of the stack) in q, along with @q^ instead being used to do the same but also pop 2 off the stack.

I initially saw the example on this here webpage at the very bottom: https://horman.net/avisynth/rpn.php

Let me know if you think it'd be worth adding.