Yes, Emeditor can do columnar selections, but edits on this selection are not applied to all lines of a selection.
F.e. make a column selction of zero width and begin to type:
Emeditor: the text appears on only one line, on the other lines nothing happens.
BoxEditor Plugin or Boxer Texteditor: the typed text appears on all lines – which I think is the natural behaviour.
Theres is a demo at http://www.boxersoftware.com/pgbwin.htm.
If you select some text in box mode and type something, the typed text should appear on all lines.
This is for example useful to prefix some lines with something or to replace the prefix with something else, or to fill columns in a table with a default text.