Hi Rafael, to scan the negs with the sprocket holes, simply put them directly on the scanner glass, emulsion side down and cover them with a glass from a picture frame f.e. If you get newton rings, use anti reflective coated glass. Do the framing on the scanner manually. That's how I scan all my negs with the Canoscan 8800F and get even better scans. I also got a used V500 without any film holders and it works to like a charm.
Best - Reinhold