It's easy enough to take a flat file (with rows as records and columns as fields) and dump it into a single Excel spreadsheet. However, I want to extend the "2-dimensional" -ness of the standard way to include another dimension. This does what I want:

$output = [
               [ [0],[0],[0] ],
               [ [1,1,1],[1,1,1],[1,1,1] ],
               [ [2,2,2],[2,2,2],[2,2,2] ],
               [ [3,3,3],[3,3,3],[3,3,3] ],
               [ [4,4,4],[4,4,4],[4,4,4] ],
               [ [5,5,5],[5,5,5],[5,5,5] ],
               [ [6,6,6],[6,6,6],[6,6,6] ],
               [ [7,7,7],[7,7,7],[7,7,7] ],
               [ [8,8,8],[8,8,8],[8,8,8] ],
               [ [9,9,9],[9,9,9],[9,9,9] ],
              ];

#...other code that sets up the Excel sheet...

my $Book = $Excel->Workbooks->Open("$excelfile");

for $i (1..9) {
  my $Sheet = $Book->Worksheets("$i");
  $Sheet->Range("A1:C3")->{'Value'} = $$output[$i];
}
[download]

In this case, I have 9 sheets, named literally "1" through "9". Sheet "1" has the number 1 in cells A1:C3, Sheet "2" has the number 2 in cells A1:C3, etc. But I cannot define the "3-d" array all at once as in the example. I have a _huge_ file to deal with, one line at a time. I have a field which I want to use to define the sheet name. As I process the flat file, I want to push records into reference arrays specific to the sheet. This does the trick for dumping the flat file into one Excel sheet:

open (FILEIN,"$filein") or die "Open $filein failed: $!";
while (<FILEIN>) {
    @data = split;
    push @$output, [@data];
}    
close FILEIN;

#...other code that sets up the Excel sheet...

my $Book = $Excel->Workbooks->Open("$excelfile");
my $Sheet = $Book->Worksheets("$sheetname");

# ...other code that determines
#       $begcol,$begrow,$endcol,endrow

$Sheet->Range("$begcol$begrow:$endcol$endrow")->{'Value'} = $output;
[download]

So how do I take this line:

push @$output, [@data];
[download]

and add the extra dimension? $data[1] has the sheet name I want to use. I tried

push $$day_output[$data[1]], [@data];
[download]

but it doesn't compile and complains thus: "Type of arg 1 to push must be array (not array element) at blah blah blah..." I'm new to references so perhaps this is easy with the right syntax... Thanks, Scott Job