If you create the IRTFExportParams object and use it in the Export method (Outproc engine loading only), you will encounter the following error:
Internal program error: /Builds/TFS/FREngine_Unix/FineObjects/Inc/Errors.h, 140. com.abbyy.Outproc.FREngine.EngineException: Unknown COM error: 800040
Pass "0" as value of that property to the Export method as a workaround or if you need to use settings that are in RTFExportParams, then you can use the LoadProfile method.
For example, add your settings in the profile.ini and load it with the following line of code:
There is a section in the Developer's Help called Working with profiles that will help you to use the necessary settings.