First of all you'll need partition the slots within the library so that you can point a job to the specific slot you require, then you'll need to create an individual job for each of the 10 days, with each jobs pointing to it's specific slot.
If you just have one job and the library not partitioned then Backup Exec will select the media to use based on the time since it was last allocated, eg the oldest tape will go first. In theory you'd think this would allow you to do it easily, but in practice it doesn't take long with the occasional hiccup with your backups before the backups are out of order and you no longer have a reliable system.
On the good side, if you make sure you go through Tools, Options with Backup Exec before creating any of the jobs you can set a lot of the options to be default, then create one selection list which will be used by all your backup jobs, so when you actually create the jobs themselves, the only two things you should need to configure individually is the slot that the tape will use, and the backup schedule for that job.
