How I can give file permission in CVS

Hi,

I have a project in which i have more than 10k files are available. I don't want to give permisson to access all the java code to all. Suppose there are 500 files available which is an architecture level files, this i don't want to show any one of the team except some of the senior members. How this can be done in CVS. Please put a light on it.

Thanks And Regards
Rasa