Maybe I didn't make myself clear. (English isn't my first language)
So I have made a print with ABW, color toned. On the print, there is a 129 steps target.
I measured the target, and that is my aim.
If you have the measurements, just fill in the 129 step target image that's first assigned to an RGB colorspace like Adobe RGB, with the L*a*b* values from the measurement.
And now, I want to mimick my "original neutral gray" 129 steps target, print out with a RGB ICC profile and get the same result as my toned B&W print with ABW.
Then you have an image that looks like your print. It can be printed in regular color mode using Abs. Col. to re-create the same printed image.
Is that more clear?
I've tried to use my measurement with CTPro and make an abstract profile. But seems like that doesn't do much to simulate my ABW print.
An abstract profile could work but I don't know of anyone that has published such a process. However, the ICC profile created by the program in my github link can be used to create an image of a ABW print in a standard working space including Lab by the following process:
1. Convert a B&W image in an arbitrary colorspace (Adobe RGB, sRGB, etc) to rgb device space using the B&W icc profile created by the github program in Photoshop.
2. Then convert back to Lab, or any desired RGB colorspace using either Abs. or Rel. Col. depending on whether you want the white patch scaled to L=100 or to actual paper white.
You can then view or print the image using either Abs. or Rel. Col. depending on what you selected earlier. It will match the print using ABW. At least to the extent your standard ICC printer profile is, itself, accurate.