One area where I had luck was here:
http://www.warmuseum.ca/cwm/exhibiti.../intro_e.shtml
The Hamilton Spectator kept a tremendous archive of all their war articles, and indexed them by topic... they are searchable. Not by name, but by subject. For example searching Dieppe casualty will get you many hits, but searching by a name will nto work because you have to load each page (as a .pdf) then you can search it.
My Grandfather was also at Dieppe, Royal Hamilton Light Infantry. He was wounded immediately upon landing, and through searching I found his name and photo listed among the casualty lists that were published daily by the newspaper.
At the very least your relative should be listed, along with his next of kin if he was wounded, killed or captured. Because my Grandfather was from Hamilton, the Hamilton Spectator also published his photo also.
Good luck, I found it a lot of searching but very intersting.
Scott