Develop a webservice that downloads a .ppt file from a URL, converts the text into a string, .txt file or .html file and then deletes the .ppt file

I need a web service that accepts a URL of a .ppt file? as an? input e.g [login to view URL]**Money**[login to view URL] The web service should then download this .ppt file and return the text of in this .ppt file a string. It can even return it as a .txt file or a .html file but ideally it should return it as a string. Finally, after the text has been extracted, it should delete the .ppt file. This web service will be working on a hosted server space and so the server will not have MS Office installed in it.