use OLE;

$file = 'c:\path\to\file.xls';
if(!-e $file)
{
  print "File does not exist";
  exit 0;
}

$app = CreateObject OLE 'Excel.Application' || die "Can't open EXCEL $!\n";

$book  = $app->Workbooks->Open($file);
$sheet = $book->Worksheets(1);

# Retrieve
$cellA1 = $sheet->Range("A1")->{'Value'};
$cellB1 = $sheet->Range("B1")->{'Value'};

print "|$cellA1|$cellB1|\n";

# Do pre-processing
$sheet->Range("A1")->{'Value'} = 'pre';
$sheet->Range("B1")->{'Value'} = 'process';
$cellA1 = $sheet->Range("A1")->{'Value'};
$cellB1 = $sheet->Range("B1")->{'Value'};

print "|$cellA1|$cellB1|\n";

$app->{'Visible'} = 1;

# USER manual input happens here

# You can let them close when done (ctrl-f4 is quick)
while($app->ActiveWorkbook) { sleep(1); }
# Or you can give them time on time
sleep(10);
# Close it up if you do time
if($app->ActiveWorkbook)
{
  $app->ActiveWorkbook->Close(0);
  $app->Quit();
}

# Do post-processing
$app = CreateObject OLE 'Excel.Application' || die "Can't open EXCEL $!\n";

$book  = $app->Workbooks->Open($file);
$sheet = $book->Worksheets(1);

# Retrieve
$cellA1 = $sheet->Range("A1")->{'Value'};
$cellB1 = $sheet->Range("B1")->{'Value'};

print "|$cellA1|$cellB1|\n";

# Do post-processing work
$sheet->Range("A1")->{'Value'} = 'post';
$sheet->Range("B1")->{'Value'} = 'process';
$cellA1 = $sheet->Range("A1")->{'Value'};
$cellB1 = $sheet->Range("B1")->{'Value'};

print "|$cellA1|$cellB1|\n";

$app->save();
$app->ActiveWorkbook->Close(0);
$app->Quit();

# ThinMonk (TM)