Несколько расширенных функций по определению позиции

// Get the Position of a string, starting at the end 
// Ruckwartiges Vorkommen einer Zeichenkette innerhalb eines strings, Position von hinten 
 
function LastPos(SearchStr, Str: string): Integer;
 var
    i: Integer;
   TempStr: string;
 begin
   Result := Pos(SearchStr, Str);
   if Result = 0 then Exit;
   if (Length(Str) > 0) and (Length(SearchStr) > 0) then
   begin
     for i := Length(Str) + Length(SearchStr) - 1 downto Result do
     begin
       TempStr := Copy(Str, i, Length(Str));
       if Pos(SearchStr, TempStr) > 0 then
       begin
         Result := i;
         break;
       end;
     end;
   end;
 end;
 
 // Search for the next occurence of a string from a certain Position 
// Nachstes Vorkommen einer Zeichenkette ab einer frei definierbaren Stelle im string 
 
function NextPos(SearchStr, Str: string; Position: Integer): Integer;
 begin
   Delete(Str, 1, Position - 1);
   Result := Pos(SearchStr, upperCase(Str));
   if Result = 0 then Exit;
   if (Length(Str) > 0) and (Length(SearchStr) > 0) then
     Result := Result + Position + 1;
 end;
 
 // Get the number of characters from a certain Position to the string to be searched 
// Anzahl der Zeichen von einer definierbaren Position zur gesuchten Zeichenkette 
 
function NextPosRel(SearchStr, Str: string; Position: Integer): Integer;
 begin
   Delete(Str, 1, Position - 1);
   Result := Pos(SearchStr, UpperCase(Str)) - 1;
 end;
 
 // simple replacement for strings 
// einfaches Ersetzen von Zeichenketten 
 
function ReplaceStr(Str, SearchStr, ReplaceStr: string): string;
 begin
   while Pos(SearchStr, Str) <> 0 do
   begin
     Insert(ReplaceStr, Str, Pos(SearchStr, Str));
     Delete(Str, Pos(SearchStr, Str), Length(SearchStr));
   end;
   Result := Str;
 end;

Взято с сайта: https://www.swissdelphicenter.ch