Convert PowerPoint to Word and Word to PowerPoint

This is for a Windows 2008 R2 server, but should run on any Windows box such as WIndows 7, WIndows 8, or WIndows Server. Microsoft Office 2007 is installed, however, upgrading to 2010 is permissible if necessary to arrive at a solution. This is part of a web application. It must convert PowerPoint to Word, and Word to PowerPoint. It must do so and keep margins intact. I am using a third-party Silverlight Word editing add-on from a company named Telerik and the converted Word document must load into this properly (trial versions are available for testing). The conversion from PowerPoint to Word cannot simply convert everything to images and then embed within a word document. The word document must be editable: in other words the text must be able to be edited and its style changed. It is permissible to be a command line program. A program with a GUI is not permissible. It is permissible to be a service. Preferably the solution will have a class that can be used in the future within other application formats. It is permissible to use third party software that I will purchase. There are some restrictions to this. The total cost cannot exceed $400 for the third party software. It must do the job properly, and the Word conversion MUST load into the Telerik Silverlight Word editor. I have already tried a combination of existing third party software and have not found an adequate solution.