I need to add some code to the of several html contained in a folder on my desktop. How can i do that?

I am using a prototyping tool (Axure) on Mac and I want to add some html meta tags to the generated pages. These pages can be overwritten every time I generate the prototype. What I need is a sort of script that I can launch after re-generating the prototype, to reinsert the code. There is something for windows but it doesn't work on Mac: http://joshuamorse.com/2009/01/14/axure-protonotes-an-alternative-to-protoshare/

thanks