use strict;
use warnings;
use DBI;

<snip>

my $dbh=DBI->connect('dbi:ODBC:DSN='.$DSN, $USER, $PSWD) or die "Couldn't connect to database: ".DBI->errstr; 

my $fieldquery="
			
SELECT
<Snip>

FROM
<Snip>

WHERE
PlanSetup.PlanSetupSer=?
<snip the rest of the where clause>
";

my $sth_fields=$dbh->prepare($fieldquery) or die "Couldn't prepare statement: " . $dbh->errstr;

<Snip some stuff to get $plansetupser>

$sth_fields->execute($plansetupser) or die "Couldn't execute statement: ".$sth_fields->errstr;