符合你要求较完整的程序(含字符及生僻字):
function genahz:string;
var
c:byte;
q,w:word;
begin
c:=random(10);
if c<=5 then
begin
q:=$d8+random($1f);
w:=$a1+random($5d);
genahz:=chr(q)+chr(w);
end else
begin
c:=$41+random($19);
genahz:=chr(c);
end;
end;
procedure TForm1.Button1Click(Sender: TObject);
var
i:integer;
s:string;
begin
s:='';
Randomize;
for i:=1 to 100 do
s:=s+genahz();
memo1.lines.add(s);
end;