Let\'s say I have a website example.com
which I bought via a common domain registry nomcheap.com
.
I want all traffic to a specific subdomain
To point a subdomain to a name servers you need to create an NS record for the subdomain:
app.example.com NS ns1.appserver.com
This will make all queries go to ns1.appserver.com
*.example.com NS ns1.squaresites.com
The second record should catch all subdomains that don't have their own records (of any kind).