Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See Parameter IDs.
Parameter: Include
HAIR_LIGHT_TAG_INCLUDE
Parameter: Shadows
HAIR_LIGHT_TAG_SHADOWS
Parameter: Trans. Threshold
HAIR_LIGHT_TAG_SHADOW_TRANS_ACCURACY
Parameter: Depth Threshold
HAIR_LIGHT_TAG_SHADOW_DIST_ACCURACY
Parameter: Antialiasing
HAIR_LIGHT_TAG_SHADOW_AA_LEVEL
Parameter: Filter
HAIR_LIGHT_TAG_SHADOW_AA_USER_LEVEL
Parameter: Density
HAIR_LIGHT_TAG_SHADOW_DENSITY
Parameter: Cast Density
HAIR_LIGHT_TAG_CAST_SHADOW
Parameter: Sample Size
HAIR_LIGHT_TAG_SHADOW_SAMPLE_SIZE
Parameter: Shadow Map
HAIR_LIGHT_TAG_SHADOWS_MAP
Parameter: Resolution
HAIR_LIGHT_TAG_MAP_SIZE
Parameter: Traced Width
HAIR_LIGHT_TAG_SHADOW_WIDTH