Hi Tony
His record does not appear to have survived. You can check on Findmypast but he is not showing on the National Archives Catalogue on which these early ones are based. You could check the regimental BMDs on site such as Findmypast, as they started to record some events before civil registration started. These will tell you his regiment.
As he died before the medal for the Peninsular War was announced (1847) he did not recieve one, so you cannot use that to discover his regiment. Without his regiment there is little you can do. Even with his regiment this is 70-80 years before the army recorded a man's next of kin on enlistment.
Ken