How to get post title, user name, post message to external html page ?
 

How to get post title, user, post date, post message from vBulletin database by using "SELECT FROM WHERE..." ?

If you look in the showthread.php page, you will see a query to get the posts. Did you try looking at that and modifying it (most like taking out a bunch of stuff) to suite your needs? There are also mods and articles regarding getting posts - you can look at the queries used in those.