Replace in Files: Tagged Expressions

As mentioned in vstipFind0015 (http://blogs.msdn.com/b/zainnab/archive/2010/09/11/replace-in-files-basic-options-vstipfind0015.aspx), the "Replace with" area is the most interesting piece of the Replace in Files dialog.  It can be as simple as a literal string replacement or quite complex. Under normal situations this is just the literal text you want to use as a replacement to the "Find what"