syntax for extending a line in a script??

Hello,

     A hopefully simple question.  I use 'R' through emacs, but I suspect the
following would occur with any manner of text editor:

    - my editor has a normally quite handy feature where it will
    automatically indent to the appropriate level when I start a new line.
    However, this occasionally creates cases where there is no friendly way to
    break a long line of code into two lines which still function as one
    command.  Therefore, I need a nice way to be able to flag 'R' to know that
    the code is continuing on the next line.  Let me explain via example:

         numericColumns<- names(listOfDataFrames[[myDF]][,columnsOI])
                     [sapply(listOfDataFrames[[myDF]][,columnsOI],
is.numeric) ]

     As you can see in this case, I would *like* for these 2 lines of code to
be read as 1 line, but since the "names(<blah>)" command is sufficiently a
command on its own, 'R' see this as a completed line of code.  I could try
to break it up at different points, but emacs (and other text editors) takes
a guess as to the most intelligent way to indent, so that if I were to write
something like:

         numericColumns<- names(listOfDataFrames[[myDF]][,columnsOI])
[sapply(
                       listOfDataFrames[[myDF]][,columnsOI], is.numeric) ]


it would actually indent something more like this:

         numericColumns<- names(listOfDataFrames[[myDF]][,columnsOI])
[sapply(

listOfDataFrames[[myDF]][,columnsOI], is.numeric) ]


and as you can see, that doesn't help the issue of preventing the code from
wrapping around (and therefore doesn't help readability).  Is there some
simple way to flag that the next line is continuing?  Something like
python's "\" at the end of a line?  I tried wrapping the whole thing around
curly braces { } but that didn't work, either.

                                            Thanks!
                                                    Mike