[kh99]

In file showthread.php, search for 'showthread_query' (it's there twice but you can look at either one). That hook location is called right before the query, and you can set variables $hook_query_fields and $hook_query_joins to add fields (and join tables if necessary) to the post query.

For example, if there was an added table called more_userinfo in the database and I wanted to use all fields from it in postbit, I might use this plugin code:

$hook_query_fields .= ', more_userinfo.* ';
$hook_query_joins .= ' LEFT JOIN more_userinfo ON (more_userinfo.userid = user.userid) ';

then the fields from more_userinfo that correspond to the post author should be available in the postbit as {vb:raw post.fieldname}.