Would it be the film I'm looking for?

I'm looking for title of a film (I thought it was French and made for TV but I might be wrong!) which I saw in the mid 90's. Somebody said it could be that movie or a French film adapted or inspired by this movie.

Here is what I remember:
In the story, a psychiatrist has to leave his office (for a reason I don't remember!) with 2 or 3 of his mad or autistic patients in a car trip. I remember one of them saying "Je prendrai bien un petit yaourt!" in French ("I would like to eat a yoghurt") at some point of the trip. It's a strange to remember that kind of detail but the way he says that was quite funny and my sister and I still use this sentence! One of them (maybe the one who say the yoghurt sentence) was a 60-70-ish yo guy with white beird I think. And this character knew the whole dictionary by heart and was always saying the definition and/or etymology of words...
I also remember a kind of "Rain Man" autistic scene where a guy enters the psychiatrist office (while he's away), moves around the room and describes and counts everything: "one table, 3 chairs, 1250 sheets of paper...", something like that... Before that we saw a female character hiding herself behind curtains or anything in the room when she heard someone approaching. The autistic guy includes the woman in his description without any special emotion: "a woman behind curtains, a mirror, 2 paintings..." and eventually leaves the room! (No it's not "le Huitième Jour"...)

Any help? Thanks!

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