you can do it by using a dedicated tape drive.
1.using robtest you can send the particular tape inside you dedicated tape drive
2.then you can use your on demand tape drive for backup of that particular server
I can help explain how to create a backup in tapes, since I can not understand how to send the backup to a specific tape of several tapes that I have in the library??
You did not mention which backup product you need assistance with?
There are two Veritas backup product - NetBackup and Backup Exec.
Best to post your query in the relevant forum: