Spreadsheet::ParseExcel should be all that you'd need.

Where is the code that you've tried thus far? Where are you actually having trouble?

 
#!/usr/bin/perl -w

    use strict;
    use Spreadsheet::ParseExcel;
    use List::Util qw(max);

    my $parser   = Spreadsheet::ParseExcel->new();
    my $workbook = $parser->parse('4_19_10_Zrc01a-2.xls');

    if ( !defined $workbook ) {
        die $parser->error(), ".\n";
    }
   
    for my $worksheet ( $workbook->worksheets() ) {

        my ( $row_min, $row_max ) = $worksheet->row_range();
        my ( $col_min, $col_max ) = $worksheet->col_range();
        

        for my $row ( $row_min .. $row_max ) {
            for my $col ( $col_min .. $col_max ) {

                my $cell = $worksheet->get_cell( $row, $col );
                next unless $cell;
            
            my $i=1;
               for ($col==5 and $cell->value()==$i){
                
                       if ($col==8){
                                                      
                              print $cell->value();
                              print "\n";
                          }else {
                        $i++;
                    }                    
                    
                    }
                    
                    }
                
                }
                
                    print "\n";
                    
                
              
    
    

                }
[download]

My sheets contain values in the manner of:

A  B  
1  3
1  2
1  4
2  5
2  7 
3  10
3  0
3
3
.
.
90
90
[download]

I need to find the maximum value in column B for every corresponding value of column A. For example: The maximum value for 1 in col A is 4 in col B. My experience in perl is less than 48 hours, any help will be appreciated. Thank you.

Just put your data into a hash of arrays, and then loop on the compiled data using List::Util->max to determine the max value in each array.

The below snippet demonstrates what I'm talking about with the fake data you listed:

use List::Util qw(max);

use strict;
use warnings;

my %vals;

# Put Data into a Hash of Arrays
while (<DATA>) {
    chomp;
    my ($key, $val) = split;
    push @{$vals{$key}}, $val;
}

for my $key (sort {$a <=> $b} keys %vals) {
    my $max = max @{$vals{$key}};
    print "$key $max\n";
}

=prints
1 4
2 7
3 10
=cut

__DATA__
1  3
1  2
1  4
2  5
2  7 
3  10
3  0
[download]

If you're using a recent version of Excel, Spreadsheet::XLSX might be more appropriate. However, as already noted, without showing any code it's difficult to provide much help.

Take a look at How do I post a question effectively?.