REGEXP validation of URL in Oracle 11

Hello.

I want to make a RSS feed reader in PL/SQL, that gets feeds from one
table, parses it and inserts the news into another table.

In order to read the actual feed i need to add a rule for it in the
ACL as far as Ive found out, granting resolve and connect to the host.
So, if I want to read the feed located at http://news.domain.com/feed/type=rss2
I would grant resolve and connect for the user to host
news.domain.com.

Since neighter PL/SQL nor Regular Expressions is my strongest side at
the moment, i was wondering if someone could help me to get the
following out of the URL;

Protocol : See if it is present, or what protocol it is. That would be
everything up too ://.
Host : news.domain.com might just as well be feedme.net (without www
or news), so what is the best practice to extract it?
Path : Dont know if i realy need it, but it might be cool to have it
in as well. I guess the simples solution would be getting everything
after the third / if protocol is present, or the first / if it is not.

Any help is appreciated, so thanks in advance

-RS-