I think glob would do a lot of the work for you here, as would CGI.pm. Example:

use CGI qw(:html4);
chdir "$ENV{'DOCUMENT_ROOT'}/foo";
my @toshow = grep {-f}   # filter to only regular files
             glob('*.{png,jpg,html}');
print map {
            a({
               -style => q(Color: #000000; font-size: 13px;),
               -href => "/foo/$_"
              },
              $_
             )
           } @toshow;
[download]

I use that map because the file name is repeated in href and text. You may need to chdir or tune the file names to make the urls come out right. I have "/foo" tacked on to illustrate.

After Compline,
Zaxo