Is it possible to somehow get CTRL-X CTRL-N functionality (word completion
from insert mode) when editing the command line? From time to time I run
into the situation where I start with ":%s/", at which point in time I
realize that the word I want to substitute for is quite long and somewhere
in the current buffer, hence would prefer to just type its first few
letters and have Vim complete the rest from the current buffer. Usually in
such cases the cursor is *not* on the word in question, else I would have
used CTRL-R CTRL-W...