Suggestion (but time consuming)
find <text string with quotes and no brackets> *.* > results.txt
That will put your results into a text file named results.
Open it in notepad, use replace command for each instance?
There are third party tools that do this; I'm not sure you can batch that out, without an external program...
try SED from the unix library....
http://en.wikipedia.org/wiki/Sed