I would not use a gel, they usually have quite strong peaks in their responses. Here's one CTO response:
which has a clear green bump, which a halogen doesn't have. I've experimented with the other way around to make daylight from halogen using filters and that's not that good either, you get a very wavy response.
However, it will make a profile, and it's hard to say how much that wavy response hurts performance in practice. Probably not that much. To be on the safe side I'd use a real halogen lamp though.
Most dual illuminant DNG uses StdA as the tungsten source, which is ~2850K. 3200K might be a bit close to your daylight source to make a broad dual-illuminant profile, but it depends on what you want to achieve.