How to view and edit only a small part of a text file in Emacs

I would like to accomplish the following behaviour in Emacs and was wondering if there's an existing package that already does what I want.

I want my buffer to display only lines 30 to 60 in file myfile.txt, and simply hide the rest of the file from me.

When I scroll up to the top, I should be at line 30.
When I scroll down to the bottom, I should be at line 60.
If I edit this region, these edits should be reflected in the original file.
The region should grow/shrink as I insert/delete lines.
I should be able to open multiple regions to the same file in different buffers.

This is very close to my ideal workflow. Thanks very much for your help!

Solution

Try library Narrow Indirect (narrow-indirect.el)

It provides simple commands to create an indirect buffer that is a clone of the current buffer and that is narrowed to a particular portion of it. By default, it helps you distinguish such indirect buffers from non-indirect buffers, by using a buffer-name prefix (default I-) and by using a different face for the buffer name in the mode line.