How do I use MSProject - Document Export?

I'm trying to use: Microsoft.Office.Interop.MSProject Document Export to export my excel file to PDF as an alternative to Worksheet.ExportAsFixedFormat which causes some HRESULT problems like:

Exception from HRESULT: 0x800A03EC

I have no idea how to use MSProject, but here's what I've tried:

1. Added the MSProject Reference to my WPF Project: Microsoft.Office.Interop.MSProject (Version 15.0.0.0)

2. Replaced my Worksheet.ExportAsFixedFormat code with:

   Microsoft.Office.Interop.MSProject.Application mainMSProjectApplication = new Microsoft.Office.Interop.MSProject.Application();
   mainMSProjectApplication.DocumentExport(path, Microsoft.Office.Interop.MSProject.PjDocExportType.pjPDF, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing);
   

I get an exception on the first line:

Retrieving the COM class factory for component with CLSID {36D27C48-A1E8-11D3-BA55-00C04F72F325} failed due to the following error: 80040154 Class not registered (Exception from HRESULT: 0x80040154 (REGDB_E_CLASSNOTREG)).

3. Then I tried: Windows Key > "Run": regsvr32 "C:\Program Files (x86)\Microsoft Visual Studio\Shared\Visual Studio Tools for Office\PIA\Office15\Microsoft.Office.Interop.MSProject.dll"

I then get this Error:

The module "C:\Program Files (x86)\Microsoft Visual Studio\Shared\Visual Studio Tools for Office\PIA\Office15\Microsoft.Office.Interop.MSProject.dll" was loaded but the entry-point DllRegisterServer was not found.

Any help would be appreciated

It seems my:

Exception from HRESULT: 0x800A03EC

Was caused by me specifying a path that some Users didn't have permissions to write to.

Changing the path in ExportAsFixedFormat to the "My Documents" directory fixed the problem.

As kennyzx commented:

"This is not the right path to go. MSProject is the library for another Office file type and you cannot use it to automate Excel files"