[Exim] Exim setup

Hallo all
excuse the ignorance of some of the questions here but I am just switching
from sendmail.
I use Exim 4.12

I have the following in the exim config file
domainlist local_domains = @
domainlist relay_to_domains =
hostlist relay_from_hosts = 127.0.0.1

Now if I want to have these values in theire own seperate files I am not sure
how to do it.
can I use?

domainlist local_domains:
                file = /etc/exim/localdomains
                search_type = lsearch
domainlist relay_to_domains :
                file = /etc/exim/relaydomains
                search_type = lsearch
hostlist   relay_from_hosts:
                file:/etc/exim/access
                search_type = lsearch

If this is not correct please let me know why.

Mozzi