How do I Augment Active Directory and CRM roles in Visual Studio?

Question

I have a custom solution that allows users to login via CRM and this works fine. Also, users who can can login with windows authentication and this works fine. I need to combine the roles such that when a user logs in with windows authentication, it will check to see if the user is in CRM and add any additional roles from CRM to the current users roles. I have been provided with the queries needed to access the CRM database I am just not sure where in the process this piece will go and how to implement it.