Thanks a lot monks! Been a big help! Combining all your comments... 

use strict;
use warnings;
open "SOURCEFILE", '<', "source.cbl" or die "Can't open: $!";
open "TARGETFILE", '>', "source.ada" or die "Can't open: $!";

while (defined (my $line = <SOURCEFILE>)) {
    if ($line =~ s/WORKING -STORAGE SECTION\./declare/) 
    {
        print TARGETFILE $line;
    } 
    elsif ($line =~ s/PROGRAM -BEGIN\./begin/)
    {
        print TARGETFILE $line;
    }
    elsif ($line =~ s/DISPLAY/PUT/) 
    {
        print TARGETFILE $line;
    } 
    elsif ($line =~ s/ACCEPT/GET/) 
    {
        print TARGETFILE $line;
    }
    elsif ($line =~ s/PROGRAM -DONE\./END;/) 
    {
        print TARGETFILE $line;
    } 

}

close SOURCEFILE or die "Can't close: $!";
close TARGETFILE or die "Can't close: $!";

[download]
Tried the array pairs GrandFather but i got a blank target file... I wonder why.... hmm.... <;

In reply to Re^2: Converting a source code by oblate kramrdc
in thread Converting a source code by oblate kramrdc

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