Lambesc is a commune of 7,934 people ( 2004 ) . It is found in the region Provence-Alpes-C Ã te d'Azur in the Bouches-du-Rh Ã ne department in the south of France . Lambesc is a commune in the Bouches-du-Rh Ã ne department in the Provence-Alpes-Cote d'Azur region in southern France .