Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See Parameter IDs.
Parameter: Direction
HAIR_TOOL_COMB_DIRECTIONParameter: Strength
HAIR_TOOL_COMB_STRENGTHParameter: Spline
HAIR_TOOL_COMB_SPLINEParameter: Texture
HAIR_TOOL_COMB_SHADERParameter: Curve
HAIR_TOOL_COMB_CURVEParameter: From Root
HAIR_TOOL_COMB_FROMROOTParameter: Prevent Intersection
HAIR_TOOL_COMB_INTERSECTParameter: Geometry Weighting
HAIR_TOOL_COMB_WEIGHTEDParameter: Weight
HAIR_TOOL_COMB_WEIGHTParameter: Limit
HAIR_TOOL_COMB_LIMIT_DISTANCEParameter: Distance
HAIR_TOOL_COMB_DISTANCE