my @values;
while (<DATA>)
{
   if ( (/\=$chrom$/.../^v/) =~ m/^\d+(?<!^1)$/ ) #skip /start/ and /end/
   {
      my ($tag,$value)=split;
      push (@values, $value) if ($tag >= $start and $tag <= $stop);
   }  
   else {last if @values}  #optional 
}

print "@values";   #prints: 0.007 0.004 0.002