SQLCMD -S SqlServerName\SqlInstanceName
BACKUP DATABASE VeeamBackup TO DISK = 'C:\BackupDB2016.06.09.bak'
quit
If you need to run sql script you can proceed in this way:
SQLCMD -S SqlServerName\SqlInstanceName -i C:\temp\sqlscript.sql -o
C:\temp\sqlscript.txt
SQL management Studion download you can review this veeam article where I copied and paste text:
https://www.veeam.com/kb1761