nPos Function in Pascal

pos := nPos('/', 'c:/mypath/to/somefile/', 3);

pos = 13

function nPos(C: char; S: string; N: byte): byte;
var
  I, P, K: Integer;
begin
  Result := 0;
  K := 0;
  for I := 1 to N do
  begin
    P := Pos(C, S);
    Inc(K, P);
    if (I = N) and (P > 0) then
    begin
      Result := K;
      Exit;
    end;
    if P > 0 then
      Delete(S, 1, P)
    else
      Exit;
  end;
end;