Adding keywords in header or footer for Office documents

The objective of this program is to build a program that can add a Keyword to the header or footer of an office document. The program should compile into a Win32 DLL or COM DLL that has following function - /* pstrKeyword : Null terminated string containing keyword. (Assume this will not be longer than 20 Unicode characters) pstrFilePath : Null terminated string containing path of the file in which this should be added pWhere : The value specifies where to add the keyword - 1 - Left Header 2 - Right Header 3 - Left Footer 4 - Right Footer Return : It should return 1 if the operation was successful else return -1 */ int addKeyword(char * pstrKeyWord, char * pstrFilePath, int pWhere); Please note - 1. It should support file formats - doc, docx, rtf, xls, xlsx, ppt, pptx, odt, ods, odp 2. The keyword should appear on every page of the document. The document may have different sections. It should appear on every page of every section. 3. If the document does not have anything else placed in that position then it should just use that space. If there is some other header or footer already in that place then it should appear above that in a new line for header and below that in a new line for footer. 4. The code should run on all flavors of Windows - Windows XP, Windows Vista, Windows 7, Windows 8. It should run on both 32 bit and 64 bit version. 5. Ideally your code should not need MSOffice. If the code needs MSOffice to be installed then it should work with Office 2007, 2010, 2013 - 32 bit and 64 bit editions. 6. If you plan to use any other 3rd party library then you should confirm that with us before accepting the project.