You cannot assign tapes or slots to specific jobs. Backup Exec manages all the media for you with media management rules.
The closest you can get to having specific slots for specific jobs is to partition the library into multip logical libraries. In my opinion, this usually creates more problems than it solves, especially for small libraries.
Before you start partitioning your tape library, be aware that if BE is unable to find a suitable tape in the target partition then your job will fail.
I would suggest that you read the tape management section of the Admin Guide to learn how to manage your tapes.
Also, read my article below on why assigning specific tapes to specific tapes is not necessary.
Thanks for the article great read, makes perfect sense however each tape is 10tb uncompressed and the data being backed up is significantly less. I wanted to split up the jobs for vm's and client data so that i can archive the tapes accordingly without having to replace the entire library.
i remember doing exaclty as you were describing back in the day (monday - friday, weekly, monthly) - single tape usage and then having to pop in another when the tape was all used up because someone dumped some movies on the network... In any case, the partition solution is perfect for my scenario and given the amount of free space there is plenty of room for expansion.