note: Ideally this Twine related question should be within the Authoring > Twine category, assigning it a Harlowe related tag would help any person answering it know the name and version of the story format used.
There are a number of different methods you can use to access to the engine’s internals, most of them involve using a Scope Escalation hack of one form or another.
One example of such a hack is Furkle Industries’ “Harlowe Textbox Input” extension which uses a set of custom functions (commented on here) to gain access to the engine’s (story variable) State system.
I’ll just join the Cult of Greyelf.
Thank you, you are the best.