How to change a single CMYK value as a percentage of another value?

No not exactly. I know the value boxes can do the math equations for me. I was hoping to reference a value from another box in the equation, like referencing another cell in Excel. Do you know if Illustrator has this capability as far as the CMYK value boxes go? I've tried poking around in the Recolor Artwork feature as well but I haven't seen any way to go about this.

Alternatively, it would be helpful to me is if I could select multiple artworks and then recolor one of the CMYK values by dividing all the current values by the same number. For example, I select 2 artworks and then divide the C value by 1.5. So if one artwork begins with C = 2 and the other artwork begins with C = 5, both are divided by 1.5 so the result is C = 1.33 for the first artwork and C = 3.33 for the second artwork. Is this possible in Illustrator?

Thanks so much for your response. 🙂