Redirect external domain to subdirectory

I'm trying to achieve the following 2 tasks:

1. Redirect a domain name from Godaddy to a subdirectory of a Winhost site. In this case, I need the new domain to mask the subdirectory domain. Example:

///PRIOR REDIRECT
foo.mySiteDomain.com redirects me to my site.
foo.mySiteDomain.com/About redirects me to the About page of my site.

//AFTER REDIRECT
newDomain.com redirects to foo.mySiteDomain.com
newDomain.com/About redirects me to the About page of my site. Without letting users know that the physical(?) path of the subdirectory is "foo.mySiteDomain.com/About", in other words, the "foo.mySiteDomain" would never appear.

2. Redirect a subdomain to a subdirectory, without letting the user know the physical path of the domain.
For example, right now I have the domain app-rd.com and a subdirectory called "funbru". I also set up a subdomain in the form of "funbru.app-rd.com". I created a default file in my root folder that redirects "funbru.app-rd.com" to "app-rd.com/funbru" BUT when the redirect finishes, it presents the following address:
funbru.app-rd.com/funbru
is there any way I can just make it so it seems as
funbru.app-rd.com
and if I go to the About section of the page it goes to funbru.app-rd.com/About, for example?

Thank you.

 

Any Tutorials that could help me achieve that? Specially the part of redirecting a domain to a subdirectory and making it so the URL doesn't change (unless you go to a route of the app ofc)