hidden question auto answered based on url - by: davideunipi

I wish to create a survey with a hidden question, and limesurvey should fill the answer with a value read from the url, e.g.
mylimesurveysite.com/index.php/123456 is the standard url for my survey
I would like to navigate to mylimesurveysite.com/index.php/123456/abcd where I find the same 123456 survey and the question n. 1 is automatically filled with the answer "abcd"

I suppose that I will need some hacking on the code, anyone has alreay tried something similar?

Thank you
Davide Borgioli
Università di Pisa - Italy