Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See Parameter IDs.
Parameter: Use Fields
POINTSELECTIONTAG_ENABLEFIELDSParameter: Restore Selection
POINTSELECTIONTAG_COMMAND1Parameter: Select Points
POINTSELECTIONTAG_COMMAND3Parameter: Hide Points
POINTSELECTIONTAG_COMMAND5Parameter: Select and Hide Others
POINTSELECTIONTAG_COMMAND2Parameter: Deselect Points
POINTSELECTIONTAG_COMMAND4Parameter: Unhide Points
POINTSELECTIONTAG_COMMAND6Parameter: Tolerance
POINTSELECTIONTAG_FIELDTOLERANCEParameter: Use Deformed Points
POINTSELECTIONTAG_DEFORMEDSTATEParameter: Fields
POINTSELECTIONTAG_FIELDS