Library and Archives Canada announced yesterday that the project to digitize all Canadian Expeditionary Force service files has reached the name, Jellyman, in box 4,810. There is a total of 640,000 service files in 10,686 boxes, so they are closing in on the midway point.
You can begin your search on LAC’s Soldiers of the First World War: 1914–1918 database.
LAC is digitizing the service files systematically, which roughly corresponds to alphabetical order. Over the years, however, the content of some boxes has had to be moved and, you might find that the file you want, with a surname that is supposed to have been digitized, is now located in another box that has not yet been digitized.