Yes, but my main question isn´t that...I have even seen 
http://kb.mozillazine.org/Links_to_local_pages_don%27t_work about how Firefox cannot open local files for security reasons. And how to workaround this using an extension.
My main question is how a web page (stored on "html" directory) should link to a file on  "files" directory.
Either using file://  or http://
See my files on each directory:
[root@marreco busca]# pwd
/home/e-smith/files/ibays/busca
[root@marreco busca]#
[root@marreco busca]# ls -la files/
total 204
drwxrwsr-x  2 root       shared  4096 Jul 21 21:15 .
drwxr-xr-x  6 root       root    4096 Jul 21 21:23 ..
-rwxrw----  1 massignan  shared 47104 Aug 21  2006 ALAN.doc
-rwxrw----  1 massignan  shared 24576 Mar 13  2007 ARI.doc
-rwxrw----  1 massignan  shared 34816 Feb  7  2008 AUTO.doc
-rwxrw----  1 tedesco    shared  2533 Feb 14  2008 Calculo.pdf
-rwxrw----  1 tedesco    shared 42496 Sep 25  2007 COML.doc
-rwxrw----  1 secretaria shared 38400 Jun 25  2008 Deve.doc
[root@marreco busca]# ls -la cgi-bin/
total 676
drwxrwsr-x  2 root shared   4096 Jul 21 21:17 .
drwxr-xr-x  6 root root     4096 Jul 21 21:23 ..
-rwxrwxr-x  2 root shared 108447 Jul 21 20:39 index.cgi
-rw-r--r--  1 root shared 439028 Jul 21 21:17 index.swish-e
-rw-r--r--  1 root shared    270 Jul 21 21:17 index.swish-e.prop
-rwxrwxr-x  2 root shared 108447 Jul 21 20:39 swish.cgi
-rw-rw-r--  1 root shared    319 Oct 15  2010 .swishcgi.conf
You can see "busca" is an ibay.
I´d like to know how create an html file on html dir to point to one of those files on files directory. Let´s use aaaa.doc for example
The swish-e program try to use file:// and that´s the only option for files on personal directory of lawyers.
I´ll need to instruct Swish-e to create those links, so I need to understand how they work before be able to teach swish-e 

Regards
Jáder
Reference : 
http://support.mozilla.com/en-US/kb/Links%20to%20local%20or%20network%20pages%20do%20not%20work