Visual blcok: Force insert ("I") to insert even in rows that have no characters

When coding, I often press ctrl-V, highlight a column of text of a certain
height, then press "I" to insert (say) a comment delimiter or a line
continuation flag character. This doesn't quite work on short rows of text
that end before the column that I'm highlighting. I would like vim to
append the required spaces to permit the insertion. Is there a switch for
this?

--
--
You received this message from the "vim_use" maillist.
Do not top-post! Type your reply below the text you are replying to.
For more information, visit http://www.vim.org/maillist.php

---
You received this message because you are subscribed to the Google Groups "vim_use" group.
To unsubscribe from this group and stop receiving emails from it, send an email to vim_use+unsubscribe@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.