Poor man's solution:

#!/usr/bin/perl
use strict;
use warnings;
use LWP::Simple
my $url = 'http://some.domain/some/path/to/file.htm';

my $content = get $url;
$content =~ s|</head>|<base href="$url"></head>|is;

print "Content-type: text/html\n\n$content";
exit(0);
[download]

If you want to keep all links internal, it will take a while - especially if you take some time to think about why you want to mis-represent content's origin to users on that large a scale.

.02

cLive ;-)