If you are scanning trannies, you can create an ICC profile for your scanner, for a particular film.
My understanding is that you create the profile using settings that you'll repeat for actual film to be scanned. This includes black and white points, etc. Then you scan your film in *exactly* the same way that you scanned the profile target. No deviations. At all. As in no adjustments, auto or manual.
You can't create a valid ICC profile for negatives films, either B&W or color. Too many variables, such as density range. If you wondered why you couldn't find an ICC profile target for a negative film, that's why.
All that said, there's a pretty fair argument to be made against using ICC profiles for any scanning. And a pretty fair argument to be made for using ICC profiles for scanning trannies. It usually devolves rather quickly into a religious argument. I'm not up for it, so I'm not going to extend an opinion one way or the other.
it works out close enough for me when doing trannies too, and so since I'm not trying to match some art directors idea of what my colour should look like (compared to his product) I don't really mind.