...
   WHERE asof_date = '$test_date'
   ...

##</code><code>##

   ...
   s/\$test_date/$test_date/g;
   ...

##</code><code>##

#===============================================#
$ss_source_file   = "C:/code/mla/tmp.sql";
$test_date = "30-APR-2011";
$schema    = "DEV";
#####################
%trancd_sql = (); # each SQL in a hash with a 
                  # transaction number and associated SQL

open(SS_SOURCE, "< $ss_source_file ") || die "Can't open SQL source file! $!\n";
while (<SS_SOURCE>) {
   if (/^;/) {    # the end of each SQL 
      $end_sql   = 1; 
      $begin_sql = 0;
      $trancd_sql{$tran_code} = $sql; ## push each  tran_code/SQL into hash
      $sql = '';
      $tran_code = '';
   }
   
   ## beginning of an sql
   if (/^\s*-{2,}\s*tran_code\s*\d{4,}/) { 
      ($tran_code) = $_ =~ /^\s*-{2,}\s*tran_code\s*(\d{4})/;
      $begin_sql = 1;
      $end_sql   = 0;
   }

   if (($begin_sql == 1) && ($end_sql != 1)) {
      #s/\$test_date/$test_date/g; # works if uncommented
      #s/\$schema/$schema/g;       # works if uncommented
      $sql .= $_;
   }
   
}
close(SS_SOURCE);

$trcd = 1;
while ($trcd > 0) {
   print "Enter Tran code, or '0' to exit: ";
   $trcd = <STDIN>;
   chomp($trcd);
   print $trancd_sql{$trcd};
}   
#====================================================#

##</code><code>##

#=====================================================#
-- tran_code 1752
SELECT *
   FROM $schema.TRANSACTOPMS
      WHERE TRANSACTION_CD IN ('146','147')
      AND AMT < 0
      AND ASOF_DATE = '$test_date'

;
-- tran_code 1753
SELECT *
      FROM $schema.TRAN
      WHERE TRANSACTION_CD IN ('196','197')
      AND ASOF_DATE = '$test_date'
      AND RECORD_VERSION_NBR = '0'
;

-- tran_code 1758
SELECT COUNT(SS_NO), SUM(ABS(SS_PRINCIPAL))     
      FROM $schema.SS_MLA_TRAN
      WHERE INVESTOR_ID = '195'
      AND MAN_CD = '4'
      AND ASOF_DATE = '$test_date'
      AND RECORD_VERSION_NBR = '0'
      and GROUP_ID = 'PCC'
;      

-- tran_code 1765
      ... and so on, you get the idea
;      
#==================================================#

##</code><code>##

SELECT *
   FROM DEV.TRANSACTOPMS
      WHERE TRANSACTION_CD IN ('146','147')
      AND AMT < 0
      AND ASOF_DATE = '30-APR-2011'

##</code><code>##

SELECT *
   FROM $schema.TRANSACTOPMS
      WHERE TRANSACTION_CD IN ('146','147')
      AND AMT < 0
      AND ASOF_DATE = '$test_date'