Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See Parameter IDs.
Parameter: Set Reference Pose
TCD_EXTRACTRESTPOSEParameter: Go to Reference Pose
TCD_APPLYRESTPOSEParameter: Extract Skeleton
TCD_EXTRACTSKELETONParameter: Add Body Part
TCD_ADDBODYPARTParameter: Remove Body Part
TCD_REMOVEBODYPARTParameter: Load Preset...
TCD_LOADPRESETParameter: Save Preset...
TCD_SAVEPRESET