How to define a domain account in a project with Forms authentication?

Question

ASP.NET

Hello. There is a project with forms enabled with authentication. You need to somehow define a domain account for a specific list of users
At the moment, the following solution has been implemented:
A second site has been deployed, on which windows authentication is enabled. The user enters the first resource, if it falls under our conditions, a redirect occurs to the second resource, where his account clings and is transferred back to the first resource through the curie string
. Everything is fine on the test, but on the pre-production, we encountered the fact that redirect frauds simply make the resource inaccessible (here and redirect from https to http, and all possible proxy rules that you can’t follow). In the case of a redirect, I would like to do it all on the server side (maybe through Server.Transfer, and not Response.Redirect ?)
Now I’m looking towards virtual directories in IIS, but I didn’t find a working solution
. Please tell me if there are more correct and painless ways to bypass this problem