While your db may have other problems (which others have
made suggestions about) I'll answer with one
method of doing what you are asking for. Load your file
into @array. Then start from the top of the array looking
for a match on your first key. The first match is the
starting index for your output. Next, use a reverse for
loop, ie start at the last line of the array and decrement
by one, until you get a match. That is the last line you
want to output. Then simply print out everything from your
first index to your second index.
A quick fix that will hold off the dogs while you are
learning to program a real dbi.