Can you really redirect my way through a subdomain towards the primary domain.

Eg

anything.example.com

something.anything.example.com

must all visit example.com

and

anything.example.com/page.php

something.anything.example.com/page.php

must all visit example.com/page.php

is possible ? on the shared host ?

yah, sure that's possible. just setup a subdomain this is a wildcard (* of all apaches) and hang the VH to become the website root.

It is possible if you can get the DNS records. You need to add a b-record, with as values * and also the ip of example.com