Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See page_maxonapi_getting_started_foundations_cinema_parameters.
Parameter: Show Objects
ID_CA_XREF_SHOWOBJECTS
Parameter: Loaded
ID_CA_XREF_LOADED
Parameter: Generator
ID_CA_XREF_GENERATOR
Parameter: Reference
ID_CA_XREF_FILE
Parameter: ...
ID_CA_XREF_FILE_SELECT
Parameter: Proxy Ref
ID_CA_XREF_PROXY_FILE
Parameter: ...
ID_CA_XREF_PROXY_FILE_SELECT
Parameter: Namespace
ID_CA_XREF_NAMESPACE
Parameter: Animation
ID_CA_XREF_ANIMATE
Parameter: Frame
ID_CA_XREF_TIME
Parameter: Offset
ID_CA_XREF_OFFSET
Parameter: Scale
ID_CA_XREF_SCALE
Parameter: Position
ID_CA_XREF_PIVOT_POS
Parameter: Scale
ID_CA_XREF_PIVOT_SCL
Parameter: Rotation
ID_CA_XREF_PIVOT_ROT
Parameter: Swap
ID_CA_XREF_SWAP
Parameter: Reload
ID_CA_XREF_REFRESH
Parameter: Open for Edit
ID_CA_XREF_EDIT
Parameter: Options...
ID_CA_XREF_OPTIONS