use strict;
use warnings;
use DBI;

my $sid='MYDB';
my $user='myuser';
my $pass='mypass';

my $dbh = DBI->connect("dbi:Oracle:$sid", $user, $pass,
						 { AutoCommit => 0, RaiseError => 0, PrintError => 1 } );
my $sth= $dbh->prepare(<<SQL) or die $dbh->errstr;
    select
        (FROM_TZ(
            CAST(sysdate as timestamp)
            ,
            :TIMEZONE
        ) AT TIME ZONE :TIMEZONE ) AS MY_RESULT
    from dual
SQL

$sth->bind_param(':TIMEZONE', 'Europe/Berlin') or die $dbh->errstr;