Code:

Function PreDecode(s:string):string;

function AddNumericChar(I: Integer):string;

var

   W: WideChar;

   Buffer: array[0..10] of char;

begin

   if I = 9 then result := ' '

      else if I < ord(' ') then result := '?' {control char}

          else if (I < 256)  then   result := Chr(I)

   else

   begin

   W := WideChar(I);

   SetString(result, Buffer, WideCharToMultiByte(CP_ACP, 0,

         @W, 1, @Buffer, SizeOf(Buffer), nil, nil))

   end;

end;

var val,i,ik:integer; sq:string;

begin

for i:=1 to Length(s) do

begin

     if ( (s[i]='&') and (s[i+1] ='#') ) then

      begin

         sq := Copy(s,i+2,length(s));

         for ik:=1 to length(sq) do

         begin

           if not ( sq[ik] in ['0'..'9'] ) then

           break;

         end;

         if Copy(sq,1,ik-1) <> '' then

         val := StrToInt( Copy(sq,1,ik-1) ) else val:=-1;

         if ( (val <> -1) and (sq[ik] = ';')  )

         then

          begin

            Result:=Result+AddNumericChar(val);

            Delete(s,i,ik+1);

           end;

      end else result:=Result+s[i];

end;

end;