Only easy Code-Login for some pages

Hello,

Is it possible to set only a code-login for some pages, so that visitor needs to insert a code and then the defined sites with content for this code would be displayed?

So in my case i have hundreds of codes with 3 types of site access. With code-type-1 i can only access site ABCDEFG and with type-2 CDEF and type 3 only ABC.

You understand what i mean?

Thank you in advance,
Florian