I whipped up a quick function that allows you to quickly search for a string in a folder or project (if you use repository detection) using the commercial PowerGrep program.

Just add the following to your .emacs:

(defun power-grep-selection-folder ()
(interactive)
  (start-process "powergrep" "foo" "C:\\Program Files (x86)\\JGsoft\\PowerGREP3\\powergrep.exe" 
  "/search" "/folderrecurse" 
  (replace-regexp-in-string (regexp-quote "\/") (regexp-quote "\\") default-directory) 
  "/searchtext" (buffer-substring (region-beginning) (region-end)) 
  "/resultsoptions" "5" "1" "9" "0" "0" "2" "/execute"))

From there you can assign it a keyboard shortcut or just use it as is. If you use repository root to manage project scope you can use the following to search your current repository:

(defun power-grep-selection-project ()
(interactive)
  (start-process "powergrep" "foo" "C:\\Program Files (x86)\\JGsoft\\PowerGREP3\\powergrep.exe" 
  "/search" "/folderrecurse" 
  (replace-regexp-in-string (regexp-quote "\/") 
  (regexp-quote "\\") (repository-root buffer-file-name)) 
  "/searchtext" (buffer-substring (region-beginning) (region-end)) 
  "/resultsoptions" "5" "1" "9" "0" "0" "2" "/execute"))