yes and yes to the first paragraph's questions

since the values in the 4th column for the first data file are all within the first interval specified in my second data file, they would all be printed to the same output file, once all of those lines have been printed I wish to increase my interval from (1, 1000001) to (100001, 1100001) and repeat the process (in this case with lines not shown here but that have 4th column values within the second interval.

my interval will always be one million in size, but the start and end values are increasing by one hundred thousand