Hello,
In case you have purchased the 9.1 remote agents, you can install them on the 2 remote servers and back those up.The 9.1 agent is compatible with backup exec 9.1 only.
Refer to the following technote which helps in the install process:
Title: How to install the Backup Exec 9.x Remote Agent for Windows Servers
http://support.veritas.com/docs/253058
Hope that helps. Revert in case of doubts.
Note : If we do not receive your reply within two business days, this post would be marked ‘assumed answered’ and would be moved to ‘answered questions’ pool.
Regards.