I also needed something like this, so put together a quick tool in Excel. It does the job. Will work on any file format.
1. You will need to click on the button.
2. Give the string to be searched/replaced. (Cannot be a NULL).
3. Give the string which will be substituted. (Can be a NULL).
4. Show the folder where files reside.
5. Will get a report of changes made.
This code will hit all the files in the folder shown.
Pre-requisites:
1. Need to have macros enabled in Excel. Tools>>Macro>>Security>>Medium. (Restart Excel).
2. Set some VBA object references. Press ALT+F11. Go to Tools>>Reference, and enable as below pictured.
Incidentally, this can also be used to replace " ", with an underscore. Makes me happy...! Search/replacement pattern is case sensitive. This works well for places, where organizations do not allow employees to install applications.
File is attached. Test it first on a small bunch of files. Let me know of any issues. Tested it to work on Excel 2003/2007.