sub Read_File {
    $Index = 1;
    while(<CLAIMS>)
    {
        chomp;
        $FirstItem[$FirstItem[$Index]] = substr($_,1,8);
        $SecondItem[$SecondItem[$Index]] = substr($_,9,6);
        $ThirdItem[$ThirdItem[$index]] = substr($_,15,2);
        #File continues ad nauseum but you get the idea
        $Index++; 
    }