Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See Parameter IDs.
Parameter: Target Object
POINTPROJECTOR_LINKParameter: Projection Mode
POINTPROJECTOR_MODEParameter: Orientation
POINTPROJECTOR_ALIGNMENTParameter: Hierarchical
POINTPROJECTOR_INCLUDE_HIERARCHYParameter: Offset
POINTPROJECTOR_OFFSETParameter: Strength
POINTPROJECTOR_STRENGTHParameter: Field
POINTPROJECTOR_FALLOFF