Regex or Looping problem ?

[LI NGOK LAM]

<snipped some annoying code>

foreach my $result(@filelist)  # a script snipped was given a file list 
   { chomp ($result); 
    my $com_result = $result;
    $com_result =~ s/^$root//; 
        # $root was a defined var, where using to target the below filter focus 
        # on the rest of parameter besides from the common root.
    
    my $skip_this = 0; if (@FFW)  # FFW stands for Filter File With
    {  foreach my $filter_key (@FFW)
     { 
      $skip_this = 1 if ($com_result =~ /$filter_key/i);
      last if $skip_this;
    } } next if $skip_this;
    
    my $skip_this = 0; if (@FFO) # FFO stands for Filter files without
    {  foreach my $filter_key (@FFO)
     { $skip_this = 1 if ($com_result !~ /$filter_key/i);
      last if $skip_this;
    } } next if $skip_this;
    
    push @ret, $result if ($result);
   }

<snipped rest of code>

The problem is if I give @FFW or @FFO a values like ('.txt', '.doc')
the regex won't take care of the '.', I have try to modify like :
$com_result =~ /$->{filter_key}/i
I then get my job done with a new script, but unable to done the job 
when back to this script. So I wonder if there is something wrong 
with the 'next' statement . Anyway, I just can't figure out what's going 
wrong, any pointers ?

Thanks