Grandfathers company in 5th Cameron Highlanders?

Can anyone help me find out what company my great grandfather would have been in .I know he enlisted in 1916 in Fort William no 30509 Pte John Campbell 5th Batt Queens Own Cameron Highlanders and died of wounds 05/10/18.I have letter from nurse etc but i still dont know what company and when after training he was sent to france .I have been to Fort George and they cant advise me any further . Is there any one who could advise me and help me as i seem to have come to a stop in my research. Yours Francie