How go from directoryentry to spuser

Hello,

I need to add the users from A.D. group to a SP group. I have done the :

DirectoryEntry entry = new DirectoryEntry("LDAP://OUdfdsft Users,DC=dsfdsf,DC=com");
            DirectorySearcher mySearcher = new DirectorySearcher(entry);
            //mySearcher.Filter = ("(objectClass=*)");
            mySearcher.Filter = String.Format("(employeeID={0})", "11111");
            SearchResult result = mySearcher.FindOne();
            DirectoryEntry myDirectoryEntry = result.GetDirectoryEntry();

But I don't know how to continue afterwards.

Thank you

Christos