Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See Parameter IDs.
Parameter: Target
PREF_IMEXPORT_NODESPACEParameter: Color Management
PREF_IMEXPORT_OCIO_IMPORT_MODEParameter: Show Dialog
PREF_IMEXPORT_SHOW_IMPORT_DLGParameter: Merge on Drag & Drop
PREF_IMEXPORT_MERGE_ON_DDParameter: Verify Scripts
PREF_IMEXPORT_VERIFY_SCRIPTParameter: Flush Data
PREF_IMEXPORT_VERIFY_SCRIPT_FLUSHParameter: Show Dialog
PREF_IMEXPORT_SHOW_EXPORT_DLGParameter: PREF_IMEXPORT_INFOTEXT
PREF_IMEXPORT_INFOTEXT