How to assign permission to users on applications through active Directory?

hi Experts,

I want to use Active Directory with C# .Net.
My Problem is that i want to restrict some users on my system(which is not on any network) from accessing some applications like oracle, adobe photoshop.

How can we do this programmaticaly through C# with the hep of active directory.
How can we grant or revoke permissions from users through Active Directory.

thanks