Expanding on philcrow's last paragraph I just encapsulated your code in routines:

#!/usr/bin/perl -w
use strict;
use Win32::OLE; #or ParseExcel or whatever

my $DEBUG = 1;

#
# Subroutines
#


sub get_cell_val() {
    my ($src_sheet, $src_row, $src_col) = @_;
    if (defined $src_sheet->{Cells}[$src_row][$src_col]) {
        $_ = $src_sheet->{Cells}[$src_row][$src_col]->Value;
    } else {
        $_ = '';
    }
}

#
# Main Program
#
sub ret_files {
    my ($path)=@_;
    chdir($path) or die "Cannot change path: $!";
    return(glob('*.xls'));
}

sub main {
#... the rest of your code
}# end of main
    1;
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Got your files into a list:

C:\Temp>perl -e "require 'crow.pl'; print map{qq|$_\n|} ret_files('.')
+;" > do.dat
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Ran your script for each file independently:

perl -ne "BEGIN{require 'crow.pl'}; main($_)" do.dat
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If you really want to make things simple you can copy the above command line instructions into a batch file (.bat) and re-run it whenever you want. Update: Oh yeah, you will want to flush your output so that you can see those debug statements early on if you are going to use this for hundreds of files.