Just Plain Bob

I'm looking for the title of a movie starring Donald Sutherland, probably made in the '70's or early 80's. He plays a con man who also believes in the form of magic he professes to practice. Reads from an old book named "Powwow, or the Long Lost Friend". he takes on a young runaway as an apprentice. The book is real, by the way, and has nothing to do with Native American practices. I had seen it when it first came out, and would like to see it again, but I can't remember the name. I've looked on IMDB but there is nothing there that looks familiar. anyone have any ideas?