The lines property has not been implemented since it does not fit to the architecture of wptools which uses a tree (not list) of paragraphs
To append a line use the
Code
var par : TParagraph;
begin
if WPRichText1.CheckHasBody then
begin
par := WPRichText1.ActiveText.AppendNewPar();
// Assign the text
par.SetText('some text');
// Set properties
par.ASet(WPAT_IndentLeft, 360);
WPRichText1.Refresh;
end;
end;