Here is another version using the arrays as listed in OP and a reference that loops through each array. You could add logic to break out of the loops once the value is found.

Updated again... left out $found declaration and initialization (fat fingers).

#!c:\perl\bin\perl.exe

use strict;
use warnings;

my @lane01_1 = (200900..202543); 
my @lane01_2 = (202544..204187);
my @lane01_3 = (204188..205831);
my @lane01_4 = (205832..207475);
my @lane01_5 = (207476..210119);
my @lane01_6 = (210120..211763);
my @lane01_7 = (211764..213407);
my @lane01_8 = (213408..215051);

my $arrayref;
my $buildvar;
my $vector = 209456;
my $found = 0;

while(! $found) {
   $buildvar = "\\\@" . "lane01_" . $i;
   $arrayref = eval($buildvar);
   if(! defined @$arrayref) {
      print("vector: $vector not found\n");
      last;
   }
   for(my $j = 0; $j < (scalar(@$arrayref)); $j++) {
      if($$arrayref[$j] == $vector) {
         print("lane # is $i\n");
         $found = 1;
      }
   }
   $i++;
}

OUTPUT:
lane # is 5
[download]

Update #1: Removed some values from testing

Update #2: Included output.

Update #3: Couldn't take it - replaced outer for loop with a while loop and a bool. This also required a test to make sure @$arrayref references a valid array. If it's not, then there is no match for $vector. Original for loop included below.

for (my $i = 1; $i <= 8; $i++) {
   $buildvar = "\\\@" . "lane01_" . $i;
   $arrayref = eval($buildvar);
   for(my $j = 0; $j < (scalar(@$arrayref)); $j++) {
      if($$arrayref[$j] == $vector) {
         print("lane # is $i\n");
      }
   }
}
[download]