Napoleon's entire corps commenced their march toward London as per the established plan. The First, Second, and Third Corps were directed to proceed towards the Royal Tunbridge Wells. Meanwhile, the Fourth, Fifth, and Sixth Corps were assigned to seize control of Maidstone, and the Seventh, Eighth, Ninth, and Cavalry Reserve Corps were tasked with capturing Rochester.
For communication between the corps, the employment of spark gap radio technology, a wireless means of communication, was put into practice. They would occasionally transmit their location and distance to their targets.
Napoleon was in the third group, which was composed of the Seventh, Eight, Ninth, and Cavalry Reserve Corps. As to why he was not leading any corps is simple, he is the commander-in-chief, meaning that his role was to oversee and coordinate the entire operation rather than lead a specific corps.