Can't find DXFExport Class


I'm using Corel Type Library 18.1 with C#. In the Documentation I see, that there must be a DXFExport Class, but i can't find it with intellisense.

My Plan is to set the export options from a document (dxf file) 

I tryed to record a makro to see the settings:

I want to to the same thing that the makro does in c#


Dim expflt As ExportFilter
Set expflt = ActiveDocument.ExportEx("C:\Users\MAF18~1.HTT\AppData\Local\Temp\11528-Unbenannt-1-99c15ff2-cbe4-41d1-88d6-afc6b0744685.dxf", cdrDXF, cdrAllPages, expopt)
With expflt
.BitmapType = 0 ' FilterDXFLib.dxfBitmapJPEG
.TextAsCurves = True
.Version = 13 ' FilterDXFLib.dxfVersion2008
.Units = 1 ' FilterDXFLib.dxfFeet
.FillUnmapped = True
.FillColor = 0
End With