Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See page_maxonapi_getting_started_foundations_cinema_parameters.
Parameter: Towards
HAIR_TOOL_CLUMP_TOParameter: Keep Lengths
HAIR_TOOL_CLUMP_FIXED_LENGTHParameter: Strength
HAIR_TOOL_CLUMP_STRENGTHParameter: Curve
HAIR_TOOL_CLUMP_CURVEParameter: Rotate
HAIR_TOOL_CLUMP_ROTATEParameter: Rotation
HAIR_TOOL_CLUMP_FREQParameter: Curve
HAIR_TOOL_CLUMP_FREQ_CURVE