Hey, I have a problem because I need to make something like this:
I have a server(www.server.com) and there 2 domains: www.something1.com(on www.server.com) and www.something2.com on one (www.server.com/something2/) .
The thing is that I need to make a sub domain www.shop.something2.com which needs to be located under www.server.com/something2/shop/. The most important thing is that insted of index.php as the default page i need to make shop.php as default after entering www.shop.something2.com.

OMG. I cannot understand a thing from your question. Don't you mix domain and server document root? Give an example of what you should get in the very end.

a subdomain which dosent start with index.php but shop.php.

It begs the question, Why?

but just add shop.php to the Index list.

which index list??
I need it because i have few blogs with different name(f.e www.name.something.pl) in the same folder so I want the subdomain directing to name.php.