Un père et passe (1989)

Camille (Penelop Schallenberg) is the only child of her unmarried journalist mother Marianne (Veronique Genest). She has never known who her father is, and her mother isn't telling. However, in her rush to get to an assignment in the Middle East, her mother left behind three letters addressed to three men Camille has never heard of. When she opens the letters, she discovers that they exhort each of the men to look after Camille, as they may be her father. Naturally, Camille looks them up, letters in hand. Just as naturally, they get to know one another, squabble over who is the real father, and conspire to break her out of the orphanage she is put into when the authorities find out her mother has become a political prisoner.