Hi BJ,
I've used it many times with no problems (YES, it scares at first time).
You have a Storage Group with at least one database. Then you create a RSG and add the database you need to restore.
From Backup Exec, you restore the database without redirection. Since there is a rsg with that database, the original database wont be overwritted. When restore finish you'll be able to extract any mailboxes with exmerge.
There is another approach, a little more complicated, using a rsg in another exchange server, and then you restore redirecting to that server...
hth