On Mon, Jan 17, 2011 at 1:08 AM, Paul Madden <Paul.A.Madden@noaa.gov> wrote:

(defun rs ()
(interactive)
(let (deactivate-mark)
(save-excursion (call interactively 'replace-string)))
(exchange-point-and-mark)
(exchange-point-and-mark))

You don't need the exchange-point-and-mark calls. As a part of the Emacs commandloop, deactivate-mark is checked after executing your command, `rs'. As long as you prevent your buffer modification code from setting `deactivate-mark' to not-nil, the region should be active.

--
Le