Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See Parameter IDs.
Parameter: Position
PROTECTION_PParameter: X
PROTECTION_P_XParameter: Min
PROTECTION_P_MIN_XParameter: Max
PROTECTION_P_MAX_XParameter: Y
PROTECTION_P_YParameter: Min
PROTECTION_P_MIN_YParameter: Max
PROTECTION_P_MAX_YParameter: Z
PROTECTION_P_ZParameter: Min
PROTECTION_P_MIN_ZParameter: Max
PROTECTION_P_MAX_ZParameter: Rotation
PROTECTION_RParameter: H
PROTECTION_R_XParameter: Min
PROTECTION_R_MIN_XParameter: Max
PROTECTION_R_MAX_XParameter: P
PROTECTION_R_YParameter: Min
PROTECTION_R_MIN_YParameter: Max
PROTECTION_R_MAX_YParameter: B
PROTECTION_R_ZParameter: Min
PROTECTION_R_MIN_ZParameter: Max
PROTECTION_R_MAX_ZParameter: Scale
PROTECTION_SParameter: X
PROTECTION_S_XParameter: Min
PROTECTION_S_MIN_XParameter: Max
PROTECTION_S_MAX_XParameter: Y
PROTECTION_S_YParameter: Min
PROTECTION_S_MIN_YParameter: Max
PROTECTION_S_MAX_YParameter: Z
PROTECTION_S_ZParameter: Min
PROTECTION_S_MIN_ZParameter: Max
PROTECTION_S_MAX_ZParameter: Allow Expressions
PROTECTION_ALLOW_EXPRESSIONSParameter: Allow Viewport Duplication
PROTECTION_ALLOW_DUPLICATION