use CGI;
my $q = CGI->new;

my @list  = map { $q->param('xxx'.$_) } 1 .. $q->param('xxxc');
# values now sequential in @list.

##</code><code>##

foreach my $index (1 .. $q->param('xxxc') ) {
    my $value = $q->param('xxx' . $index);
    # now do whatever with the value
    ...
}

##</code><code>##

%INPUT = $q->Vars;