my $col; my @col; my $row; my @row; my $sheet; my @sheet;
for($col = 0; $col < 3; $col++) { push @col, "0";}
for($row = 0; $row < 3; $row++) { push @row, [@col];}
for($sheet = 0; $sheet < 3; $sheet++){push @sheet, [@row];} 
$sheet[0][1][2] = 5;
for($col = 0; $col < 3; $col++) { 
for($row = 0; $row < 3; $row++) {
for($sheet = 0; $sheet < 3; $sheet++){
print "sheet=$sheet,row=$row,col=$col,$sheet[$sheet][$row][$col]\n";
} 
}
}
##</code><code>##

sheet = 0, row = 0, col = 0, 0
sheet = 1, row = 0, col = 0, 0
sheet = 2, row = 0, col = 0, 0
sheet = 0, row = 1, col = 0, 0
sheet = 1, row = 1, col = 0, 0
sheet = 2, row = 1, col = 0, 0
sheet = 0, row = 2, col = 0, 0
sheet = 1, row = 2, col = 0, 0
sheet = 2, row = 2, col = 0, 0
sheet = 0, row = 0, col = 1, 0
sheet = 1, row = 0, col = 1, 0
sheet = 2, row = 0, col = 1, 0
sheet = 0, row = 1, col = 1, 0
sheet = 1, row = 1, col = 1, 0
sheet = 2, row = 1, col = 1, 0
sheet = 0, row = 2, col = 1, 0
sheet = 1, row = 2, col = 1, 0
sheet = 2, row = 2, col = 1, 0
sheet = 0, row = 0, col = 2, 0
sheet = 1, row = 0, col = 2, 0
sheet = 2, row = 0, col = 2, 0
sheet = 0, row = 1, col = 2, 5
sheet = 1, row = 1, col = 2, 5
sheet = 2, row = 1, col = 2, 5
sheet = 0, row = 2, col = 2, 0
sheet = 1, row = 2, col = 2, 0
sheet = 2, row = 2, col = 2, 0