= Table.AddColumn(源,"a",each Text.Replace([str],"-",[ x = List.LastN(Text.SplitAny([str],Text.Combine({"A".."z","-"})),2), 
                                                       y = List.Transform(x,Text.Length),
                                                       z = "-"&Text.Start(x{0},y{0}-y{1})] [z]))