Nope. The choices are Media Server Only and ALL servers
'Course if the script doesn't exist on a specific server, it won't run, but will fail the job because the Pre/Post job didn't run
What you could do is create two jobs
1) The Enterprise Vault job.
pre script to put it in read only
post script to call BEMCMD and release the SQL job
2) SQL job
no pre cmd
post cmd to place the vault in Full service Mode. If the restart job can ONLY be run on the Vault server, you may need top create a third job that backs up one sample file, released from the SQL job, with a post script to place the Vault in full service
Quite a kludge, I'll admit, but it SHOULD work