The following script lacks error-checking, but should give an idea of how to proceed:

#! perl
use strict;
use warnings;
use Data::Dump;

my @accts_split;
my @accts  = (23 .. 257);
my $start  =  0;
my $length =  @accts / 10;

for my $i (0 .. 9)
{
    my $end = ($i == 9) ? $#accts : $start + $length - 1;
    @{$accts_split[$i]} = @accts[$start .. $end];
    $start += $length;
}

dd @accts_split;
[download]

Output:

19:42 >perl 571_SoPW.pl
(
  [23 .. 45],
  [46 .. 69],
  [70 .. 92],
  [93 .. 116],
  [117 .. 139],
  [140 .. 163],
  [164 .. 186],
  [187 .. 210],
  [211 .. 233],
  [234 .. 257],
)

19:44 >
[download]

Hope that helps,