Pascal/Turbo Pascal - asignar un valor a cada letra individual de una palabra

uses crt;

  const

 alfabeto: array[1..27] of Char = ( 'A', 'B', 'C', 'D', 'E',

 'F','G', 'H', 'I', 'J', 'K', 'L', 'M', 'N','', 'O', 'P',

 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z');

     max = 30; {this is used for declaring ARRAY}

 type

      hexadecimal = ARRAY[1..max] OF integer;

var

     decimal: longint;

    i: integer;

    hexa: hexadecimal;

    tecla   : char  ;

    operacion, nn  : longint   ;

    palabra : string[30] ;

(***********************************************)

(* Function convierte un caracter en mayuscula *)

(***********************************************)

function mayuscula(caracter : char ): char;

begin

    if ( char(caracter) =  '' ) then

     begin

       caracter :=  '' ;

     end;

  mayuscula := upcase(caracter);

end;

(*******************************************************)

(* Function retorna un valor dependiendo del caracter  *)

(*******************************************************)

function posicion(caracter : char ): integer;

var

 su, i: Integer;

begin

 su := 0;

 for i := 1 to 27 do

 begin

   if (alfabeto[i] = mayuscula(caracter)) then

   begin

     su := i;

   end ;

 end;

    posicion := su;

end;

function cantidad(S: string): longint ;

var

 I: Integer;

 suma : longint ;

begin

 suma  := 0;

 for I := 1 to Length(S) do

 begin

   suma :=  suma + posicion(S[I]);

 end;

   cantidad :=  suma ;

end;

    PROCEDURE convert(decimal: longint; VAR i: integer; VAR hexa: hexadecimal);

    {This procedure works the conversion}

    BEGIN

    i := 1;

    WHILE decimal <> 0 DO

    BEGIN

           hexa[i] := decimal MOD 16;

        decimal := decimal DIV 16;

           i := i + 1;

    END;

    END;

   PROCEDURE writetothescreen(i: integer; hexa: hexadecimal);

   VAR j: integer;

   BEGIN

   write( 'Convertido  ',' ', ' en hexadecimal es ');

   {This is how you make a hex number}

   FOR j := (i - 1) DOWNTO 1 DO BEGIN

   IF hexa[j] < 10 THEN

   write(output, hexa[j])

   ELSE BEGIN

   {Here, program checks for number larger than 10 to write a letter instead of number}

   CASE hexa[j] OF

   10: write(output, 'A');

   11: write(output, 'B');

   12: write(output, 'C');

   13: write(output, 'D');

   14: write(output, 'E');

   15: write(output, 'F');

   END; {End of Case}

   END; {End of ELSE}

   END; {End of FOR loop}

   END; {End of Procedure}

(************************)

(* Programa principal   *)

(************************)

begin

 clrscr;

   repeat

       clrscr;

      writeln;

      writeln;

      write('Ingrese una palabra: ');

       ReadLn(palabra);

        write(' ',palabra ,' = ',cantidad(palabra) );

        writeln;

        writeln;

        write('Ingrese un numero:  ');

        ReadLn(nn);

         operacion := cantidad(palabra) * nn;

        writeln;

        writeln;

        write(cantidad(palabra) , ' * ', nn ,' = ',  operacion );

        writeln;

        writeln;

        convert(operacion, i, hexa);

        write(operacion , ' '  );

        writetothescreen(i, hexa);

        writeln;

        writeln;

       write('Desea introducir otra palabra [S/N]');

       tecla := mayuscula( Readkey);

 until ( tecla <> 'S');

end.

(***********************************************)

(* Function convierte un caracter en mayuscula *)

(***********************************************)

le faltaba la Ñ

function mayuscula(caracter : char ): char;

begin

    if ( char(caracter) =  'ñ' ) then

     begin

       caracter :=  'Ñ' ;

     end;

  mayuscula := upcase(caracter);

end;

{Mira esto}

 program pruevas;

  uses

     crt;

   const

      hexa : Array[0..15] of char = '0123456789ABCDEF';

   type

     string30 = string[30];

     string20 = string[20];

   var

     texto : string30;

   function astrin(n : byte) : string20;

   begin

      astrin[0] := #2;

      astrin[1] := hexa[n shr  4];

      astrin[2] := hexa[n and 15];

   end;

   function wordhex(n : Word) : String20;

  begin

    wordhex := astrin(hi(n)) + astrin(lo(n));

  end;

  function longitehex(n : longInt) : string20;

  begin

    longitehex :=  wordhex(n shr 16) +  wordhex(n);

  end;

   procedure asignanumero(d : string30);

   var

      valor, t : integer;

      num : string30;

      numero : longint;

    begin

       for t := 1 to length(d) do

       begin

       num[t] := chr(ord(upcase(d[t])) - 64);

       num[0] := chr(t);

       if num[t] > #9 then

       num[t] := chr(ord(num[t]) + 1);

       end;

       valor := 0;

       texto := copy(num,1,length(num));

       for t := 1 to length(texto) do

       valor := valor + ord(texto[t]);

       writeln('   Entre Numero A Multiplicar ');

       write('     Numero : ');

       readln(numero);

       numero := numero * valor;

       writeln('   ',numero);

       num := longitehex(numero);

       write('   ');

       for t := 1 to length(num) do

       if num[t] = '0' then

     else

       write(num[t]);

       readln;

    end;

    begin

       clrscr;

       asignanumero('perro');

    end.