Here's my 20$ worth (.02 cents adjusted for inflation). It works for me and my setup has been improved through the intervening months. The neg I used for this demo has seen a lot of "not healthy for color negs storage" through the past 40 years, hence the color shift in parts of it. If you can look past the defects you might find it useful.

The orange cast is a mask inherent in most if not all color negs. My example is a Kodak Vericolor neg from the mid 70's processed by me in a real lab, as opposed to the kitchen sink. :)

It was copied using my Canon T-6 with a light box using the latest advanced engineering techniques and locally sourced materials (I slammed it together from what I had lying around at the time).

It was shot as a RAW image and processed in Photoshop.

First shot is the neg as it came from the camera, although this one, along with the other two were saved as a jpeg to conserve space and make for an easy upload.

I opened the original in Photoshop, went to Image,Adjustments, Levels and select the White Point selector (right eyedropper under the (Options)selector.

I clicked on the orange mask in the outside frame of film, its not exposed, just processed.

This gave me the odd color cast, at which time I went back to Adjustments and clicked on Invert, that gave me an image that was a starting point. After some color and exposure adjustments, I ended up with the final image.

It sounds like a lot when I read things over, but once you do it a couple of times it becomes a snap.

There are other ways to do it, I'm sure, this just what I use, and its a part of PS.

I hope this helped you to find a direction to go.
Lotsaluck in your efforts!

I have had good success shooting high quality digital copies of slides using a high resolution camera on a copy stand with light table in a dark room. Because of the orange cast of color negatives, I have been hesitant to convert them into digital images. In thinking the problem through, it would seem that if I shot a single digital image and then white balanced the negative image, I would have an underexposure, once I eliminated the cast. The method I came up with to get a properly exposed digital negative image is to compute the correction I would need to neutralize the orange mask, print the correction on transparent media and use it as a filter when I take the image. I would place it on the light table under the negative. After taking the image, I could invert colors and make any necessary adjustments. Before I started to buy supplies such as transparent media, I was wondering if anyone had tried a similar process.