this will open an existing excel file and allow you to make changes to it by using win32::ole object

use Win32::OLE;

# name file
my $xlfile = "c:/book1.xls";

# open application
my $excel = new Win32::OLE('Excel.Application');
#my $excel = Win32::OLE->GetActiveObject('Excel.Application') || Win32
+::OLE->new('Excel.Application', 'Quit')  or die Win32::OLE->LastError
+();
#$excel->{'Visible'} = 0;  ## 0 = Not Visible, 1 = Visible

# open workbook
my $workbook = $excel->Workbooks->Open($xlfile);

# add a new workbook
#$workbook = $excel->Workbooks->Add;

# add new worksheet
#$workbook->Worksheets->Add();

# setup active worksheet
my $worksheet = $workbook->Worksheets('Sheet1');

# write values
#$worksheet->Cells(1,1)->{Value} = "fee";
#$workbook->Worksheets('Sheet1')->Range('A1')->{Value} = 'perl writing
+ to Excel';
$worksheet->Range("A11")->{Value} = 'testing write';

#print "ERROR:" . Win32::OLE->LastError();

# save, close and quit
$workbook->Save();
$excel->ActiveWorkbook->Close(0);
$excel->Quit();
[download]

hope this helps. keep in mind you will need to alter this to do what you want.