HTML Code:
<html>
<head>
<meta http-equiv="refresh" content="0;
url=http://www.your_affiliate_link.com">
</head>
</html>
Just create a new folder on your server (SBI, for example) and paste the above code in a new page and save it as index.html
Now when you send people to
http://www.yourdomain.com/SBI it will redirect to your affiliate link.