[sibi2]

Please, I cannot find the title of a movie. I don't remember the year or name of the actors either.
Nevertheless, I remember the plot in detail (which, as a matter of fact, did not help me at all in searching through IMDB and other databases, despite my trying any keyword I could reasonably think of, considering the plot in question!. )
The plot:
In Paris, a few years after the end of World War II, a former female member of The Resistance is now a rich and successful... writer (I think), and, in spite of her not being young any more, a still attractive woman. She is in love with a much younger man (an American), who also loves her passionately (not long after the beginning of the movie, the two lovers are on their way to an official meeting, and they cannot resist having sex in the elevator). For some time they are happy together but the woman is deeply concerned about the difference in age between them, and she wants him to love someone better than her, i.e. younger. He does not agree with her at all. Under such circumstances, the woman thinks of a plan: with the help of her former comrades in the Resistance, she stages her death as if in a car accident, while leaving in her will her entire fortune to him. Being now dead for everybody, she goes to a doctor, a scientist who had an experimental, risky and painful rejuvenating method, and undergoes the treatment. She becomes a young woman, bearing only a slight physical resemblance with her former self. (The treatment also presupposed periodical injections in the neck, to alleviate the recurring excruciating pain she experiences, and to maintain her youth.) Pretending to be a young and shy translator, she makes him notice her by going to his favourite café. Struck by the resemblance with his lost love, he, who is inconsolable after her "death", gets acquainted and then involved with the young and - to him - dull translator. Eventually, he marries her. All this time, however, he still longs after her, the mature one, secretly spending time at her former house. Paradoxically, the now young woman has to fight not only a shadow, the ghost of his previous love, but HER OWN shadow! There is a scene when he shouts at her something like "...look at you! You are stupid, a banale translator!.. How could you ever compare with her?... She was beautiful, she was smart and sophisticated..." Eventually, she discovers his visits at her former house... Towards the end, there is a scene in which, in that house, she appears to him dressed in one of her old dresses. He is outraged, yelling something like: "How dare you wear her dress??!!.." I cannot remember well what happens in the end... I think she tells him the truth and soon afterwards dies.
Quite strange... I remember so many details, and yet cannot tell even the name of one of the characters, to say nothing about any other info!
Any help will be highly appreciated!
Thanks in advance!