Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See Parameter IDs.
Parameter: Enable
IRR_ENABLE
Parameter: Detail
IRR_DETAIL
Parameter: Lock to View
IRR_LOCKTOVIEWPORT
Parameter: Alpha Mode
IRR_ALPHAMODE
Parameter: Gadget Overlay
IRR_GADGETOVERLAY
Parameter: Save...
IRR_SAVE_IRR
Parameter: Save View...
IRR_SAVE_VIEW
Parameter: IRR_BITMAP
IRR_BITMAP