create a batch file and then try calling it in the job

SQLCMD -S srv -U usr -P pwd -Q "BACKUP DATABASE master TO DISK = 'E:\MSSQL10.INSTANCE_02\BACKUP\SystemDB\master.bak'

WITH NOFORMAT, NOINIT, NAME = N'System databases- Full Backup', SKIP, NOREWIND, NOUNLOAD, STATS = 10 " >> c:\111bkp.log