Today I found some information about the tool called bemcmd.exe. With this little tool you can run and create backup jobs in Symantec Backup Exec.
If you run bemcmd.exe /? >c:\bemcmd.txt a help file will be created. You can also download the file here: bemcmd.pdf
You can run a created job with the following command:
C:\Program Files\Symantec\Backup Exec\bemcmd.exe -o01 –j<backupjob>
As you can see, the backup job is started in Backup Exec.