A scheduled script such as this which has hard coded the name of the sql command file, set it to run in the folder containing the backups
echo %0 starting date /t time /t dir sqlcmd -S localhost\caserver -i "%programfiles%\custom\sql_express_database_name_backup.sql"
Which calls a SQL commands file containing this which contains the hard coded name of the database and location of backup files.
BACKUP DATABASE [My_Database] TO DISK = N'E:\Backup\My_Database' WITH NOFORMAT, INIT, NAME = N'My_Database-Full Database Backup', SKIP, NOREWIND, NOUNLOAD, STATS = 10 GO
Microsoft have a much more powerful script referenced here
Technet How to schedule and automate backups of SQL Server databases in SQL Server Express
