Suppose I have a section in a file which is in csv form, e.g.
a1, bbb1, cc1, ddd1, ee1 aa2, b2, ccc2, dd2, e2 aaa3, bb3, c3, d3, ee3 aa4, b4, cc4, ddd4, eee4
Then, suppose I want to replace an entire column, say one of the a's, b's, c's, d's, e's with the same value. To make this a little more general, assume I want to do this for any delimiter, not just comma. So, it might be a space or some other character as delimiter.
Furthermore, I want to do this interactively, treating that section of the file as a region using emacs point and mark. I'd also prefer to do this without the assistance of a package. Are there any good approaches using just the standard tools in Emacs? I'm using Emacs 24.3, but I don't want a method that is very version-sensitive.
OPTIONAL EXTRA: To make this even more general, if one could use the same method to replace an entire row with the same value, that would be even better.