Spanish General Marquis de Sita in the Peninsular War

I am transcribing the intelligence reports of Lieutenant Colonel John Grant, a British exploring officer. In a report dated 11 May 1810, he located along the Tietar River in Cabezuela del Valle. He writes the following report to Marshal Beresford:

"On the 22 Ulto, the Enemy entered Astorga, (after effecting a breach) by Capitulation, the Garrison 3000  men were made prisoners, the Enemys loss very inconsiderable, that of the Spaniards nothing, 7999 if the later made their escape on their way to Valladolid.

Within a few leagues of Astorga there is a Spanish General Garcia who has under his Command 16000 Gallacians, the Marquis de Sita has also another small Division of Infantry, with 1000 Guerrillas under a noted chief; under these circumstances the French will hardly be able to maintain themselves in Astorga consistent with Junots [sic] in respect to Ciudad Rodrigo.

Junot had 14000 men against Astorga. He remains in that City himself with 4000 and the other portion of his Army have Marched to reinforce Ney, and it is said arrived in Fuenteroble [Fuenterroble de Salvatierra] about 10 leagues from Ciudad Rodrigo in the vicinity of which City he had already 8000 men Cavalry and Infantry wth some field artillery.

Ney states his determination of taking Ciudad Rodrigo enclosing the greatest part of his Army, that both he and the Army acting against Badajos were to be reinforced, where an attack on both Citys [sic] would be made at same time to prevent the English bearing with the Chief of their Force against any one poit of the Enemys attack."

My question is does anyone know who the Marquis de Sita may be? I have checked the Spanish Dictionary of National Biography online but have not been able to identify him.

Thanks!

Bob