plperl trigger problem

Sorry I have not found a plperl group so I hope the useres of this
group can help me.

I have some csv data and some columns are in a bad format. this means
that some float values are formatet as "     ." if the are 0. So I have
made an before insert trigger that looks for these values and replaces
them but it dont work and I cannot found the mistake.

Please Help.

Here is the Trigger Function

CREATE OR REPLACE FUNCTION valid_number()
  RETURNS "trigger" AS
$BODY$
#hier die neue trigger-function
my $val = $_TD->{new};
if (ref $val eq 'HASH')
{
  my $str = "";
  foreach my $rowkey (keys %$val)
  {
     $str .= ", " if $str;
     my $rowval = $val->{$rowkey};

     #if ($temp = (val->{$rowkey} =~ m/\s*\.$/))
     if (val->{$rowkey} =~ m/\s*\.$/)
     {
       $val->{$rowkey} => 0;
     }
     $str .= "'$rowkey' => '$rowval'->'" . $val->{$rowkey} . "'";
  }
  elog(NOTICE, "\$_TD->\{$key\} = \{$str\}\n");
}
return "MODIFY";
$BODY$
LANGUAGE 'plperl' VOLATILE;

Than:
copy cot_data from 'D:/Eigene Dateien/PerlProjekte/cot/deacom.txt' with
delimiter as ',' CSV;

ERROR: invalid input syntax for type double precision: "       ."
SQL state: 22P02
Context: COPY cot_data, line 26, column change_in_open_interest_all: "
     ."

Some sample Data can be found at
http://www.cftc.gov/dea/newcot/deacom.txt

THX!
Christian