Find My Past does have some Victorian Army service records which might include the one you are looking IF it has survived. I don't have a FMP subscription myself at present but maybe a fellow forum member who does can help you out? Ancestry only has surviving First World War period records but does have most census records and the Birth, Marriage and Death indexes.
Alternatively if you live anywhere near or fancy a trip to the National Archives in Kew, London, you could have a look to see if they still exist. Many records have long since been lost although many still survive - so it is a bit hit and miss.
Another place to look is the associated regimental museum in case they have any records also.
"Don't talk to me about atrocities in war; all war is an atrocity." - Lord Kitchener