How do I do rectangular block copying?

You can do rectangular block copying in Vim using the blockwise visual mode. To start blockwise visual mode use the CTRL-V key. Move the cursor using any of the motion commands and then use the y operator to yank to visually selected text. If CTRL-V does not work as expected, it may have been remapped to CTRL-Q by the mswin.vim script which is often sourced by a vimrc on Windows machines to mimic some common short cuts from other programs.