CIE general sky model questions

Hello dear Radiance community,

I have a question about implementation of CIE general sky model into
Radiance. At the meantime I'm working on way of usage of this standard in
national building daylighting practise and very interested in it.
Please correct me if I'm wrong but as I understand this model is not
presented in latest release of Radiance software and cal-file "SSLDLum.cal"
of Dr. Phillip Greenup wasn't include. How do you think is there a possible
to write in addition source code of CIE sky luminance distribution in
"gensky.c"? If the Radiance licence and community allow maybe I can help
with it but need some clarifications about the existing
in "gensky.c" source code.

Thank You.

Sincerely,
Dmytriy Radomtsev.
Postgraduate, MArch, at Architectural constructions department,
Kiev national university of construction and architecture.