Hello Jimbo
Couldn't find him at first until I realised he was an officer, not a Private or NCO (the number of middle names pointed me in the right direction!).
Colonel Charles Jocelyn Cecil Sillery served with the 1st battalion 12th Foot throughout their service in the Afghan campaign (Apr 1879 - May 1880), taking part in the expedition against the Wazir Kugianis (Apr 1880) and commanding the detached wing in the operations in the Besud District (May 1880), including the successful action against superior numbers of tribesmen at Beninga (19 May 1880).
b. 1835, Ireland; d.1898, Guernsey.
All best - Garen
Edit: A little research ...
Ensign Jan 1853, 78th Foot. Lieutenant Sep 1854, 30th Foot. Captain Sep 1855. 1st Battalion 12th Foot 1858. New Zealand War 1866. Major May 1871. Exchanged into 2nd Battalion 12th Foot 1875. Lieutenant-Colonel 1877. Afghan War (1st Battalion) Apr 1879 - May 1880, expedition against Kugianis (Apr 1880), Besud expedition (May 1880) and commanding at battle of Beninga (19 May 1880, mentioned in despatches). Colonel 1881. Major-General 1882, appointed to command 2nd Battalion Suffolk Regiment. Retired Apr 1882.