Illustrator Scripting :: Convert RGB Value To CMYK Values

I want a script that can convert RGB value to CMYK values.
 
I've seen this thread which explains a script to round up and down:
 
[URL].....
 
but is there a script that i can actually define lets say the colour is yellow and in RGB it looks ok because its in RGB mode so you change it to CMYK and you have 6% - 9% cyan and you only want yellow
 
is there a script out there that i can say
 
if
 
cyan = 6%
yellow = 80%
magenta = 0%
black = 0%
 
then change to
 
cyan = 0%
yellow = 80&
mangenta = 0%
black = 0%
 
I don't mind writting the code for each colour that needs to be converted as it would only need defining once but how would i make this script?