Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See page_maxonapi_getting_started_foundations_cinema_parameters.
Parameter: Position
PROTECTION_P
Parameter: X
PROTECTION_P_X
Parameter: Min
PROTECTION_P_MIN_X
Parameter: Max
PROTECTION_P_MAX_X
Parameter: Y
PROTECTION_P_Y
Parameter: Min
PROTECTION_P_MIN_Y
Parameter: Max
PROTECTION_P_MAX_Y
Parameter: Z
PROTECTION_P_Z
Parameter: Min
PROTECTION_P_MIN_Z
Parameter: Max
PROTECTION_P_MAX_Z
Parameter: Rotation
PROTECTION_R
Parameter: H
PROTECTION_R_X
Parameter: Min
PROTECTION_R_MIN_X
Parameter: Max
PROTECTION_R_MAX_X
Parameter: P
PROTECTION_R_Y
Parameter: Min
PROTECTION_R_MIN_Y
Parameter: Max
PROTECTION_R_MAX_Y
Parameter: B
PROTECTION_R_Z
Parameter: Min
PROTECTION_R_MIN_Z
Parameter: Max
PROTECTION_R_MAX_Z
Parameter: Scale
PROTECTION_S
Parameter: X
PROTECTION_S_X
Parameter: Min
PROTECTION_S_MIN_X
Parameter: Max
PROTECTION_S_MAX_X
Parameter: Y
PROTECTION_S_Y
Parameter: Min
PROTECTION_S_MIN_Y
Parameter: Max
PROTECTION_S_MAX_Y
Parameter: Z
PROTECTION_S_Z
Parameter: Min
PROTECTION_S_MIN_Z
Parameter: Max
PROTECTION_S_MAX_Z
Parameter: Allow Expressions
PROTECTION_ALLOW_EXPRESSIONS
Parameter: Allow Viewport Duplication
PROTECTION_ALLOW_DUPLICATION