#!/usr/bin/perl -w

    use strict;
    use Spreadsheet::WriteExcel;

    my $workbook  = Spreadsheet::WriteExcel->new("test.xls");
    my $worksheet = $workbook->addworksheet();

    $worksheet->write   ('A1', "Hello");
    $worksheet->uc_write('A2', "Hello"); # New method

    #
    # The following will be appended to
    # Spreadsheet::WriteExcel::Worksheet
    #
    package Spreadsheet::WriteExcel::Worksheet;


    #
    # uc_write: A worksheet method that does ...
    #
    sub uc_write {

        my $self  = shift;

        $self->write($_[0], uc $_[1]);
    }