darren@barney:~/perlmonks$ cat csvin
replace_me
merry xmas
hello world
perlmonks
replace_me
just another Perl hacker,

##</code><code>##

#!/usr/bin/perl -w
use strict;

my $rim1_thecode = "csvout";
my $CSV_file = "csvin";
my $thecode = "replace_me";

if ($rim1_thecode ne "") {
    ##generate RIM1 csv file##
    open (CSVIN, "<$CSV_file") or die "Can't open $CSV_file: $!\n";
    my $outcsv_file = $rim1_thecode."\.csv";
    open (CSVOUT, ">$outcsv_file") or die "Can't open $outcsv_file: $!\n";

    my @lines = <CSVIN>;
    for my $line (@lines) {
         ##substitute $thecode with RIM1 transaction code##
        $line =~ s/$thecode/$rim1_thecode/;
        print CSVOUT $line;
   }
   close CSVIN;
   close CSVOUT;
}

##</code><code>##

darren@barney:~/perlmonks$ cat csvout.csv
csvout
merry xmas
hello world
perlmonks
csvout
just another Perl hacker,