Photoshop query: Black levels

[tobe]

Hello,
I have been working as a comic book colorist for US publishers for the past 3 years and have self-taught Photoshop Cs3 to myself over the past years.
Usually when i work on a comic book and check my blacks with a color picker it comes to:- 75% Cyan, 68% Magenta, 67% Yellow, and 90% Black

, but recently one of my publishers asked me to Ensure the blacks are:- 60% Cyan, 40% Magenta, 40% Yellow, and 100% Black.
I have tried a lot of different setting in the color setting options in Photoshop, but have not managed to get the same percentages as specified by my publisher.
I would be really be great full if someone could help me out and tell me how can i manage to do this without affecting the color quality of rest of the page, as i would not want the print quality to be affected.

[Paul]

This any use to you mate http://www.earthboundlight.com/photo...-settings.html

[tobe]

thank you Paul, but it didnt seem to help me much.