In your posts some day ago (
http://www.rejetto.com/forum/index.php?topic=4990.msg1028367#msg1028367) you didn't want such 'subtleties' like ?lang=... and user parameters for hfs. ... Now you need a kind of them, and even .... with "exactly this syntax" !!!
I am with Giant Eagle, that for values local to a template, with Java-script, we can do almost everything.
Where I see the problem, is to pass values once established by the user, to a next template. I did'nt want conditional html generation by use of parameters, because this implies a lot more work in code. Your problem might be different, and I'm sorry not to understand the visible part of your iceberg, so I dont want to dive in that cold water to see the invisible rest.
I'm also with rejetto, perhaps if you write in french, you will be better understood.