Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See Parameter IDs.
Parameter: Update
POINTSELECTIONTAG_UPDATE
Parameter: Select
POINTSELECTIONTAG_COMMAND1
Parameter: Deselect
POINTSELECTIONTAG_COMMAND4
Parameter: Hide
POINTSELECTIONTAG_COMMAND5
Parameter: Show
POINTSELECTIONTAG_COMMAND6
Parameter: Solo
POINTSELECTIONTAG_COMMAND2
Parameter: Show All
POINTSELECTIONTAG_UNHIDEALL
Parameter: Use Fields
POINTSELECTIONTAG_ENABLEFIELDS
Parameter: Tolerance
POINTSELECTIONTAG_FIELDTOLERANCE
Parameter: Use Deformed Points
POINTSELECTIONTAG_DEFORMEDSTATE
Parameter: Fields
POINTSELECTIONTAG_FIELDS