OpenOffice (LibreOffice) API for .NET

We need to create an OpenOffice or LibreOffice API that can be called from .NET. The methods we need are very simple, and basically what we need is to get and set the size of the Document Window. The Api needs: 1) Open a Document (excel, ppt, doc) and return a Handle 2) Set Windows Size of that Handle 3) Close the Document. We want that the user just can view the Document, avoid to save, delete or modify the document, or even try to open a new document using File menu. This Api will be called form .NET. This part is not easy, but I know that OpenOffice has some interfaces that can be accessed from other languages. If we cannot use them, we can find simple ways to call our API interface from .NET. Then we can add more methods to our class, but this are the basics that we need fast. Please, any bidder need to come with ideas. If you can do it, you have to show us that your plan is feasible and you already have the knowledge to do this. Good luck,