I think, you don't have to change the DB name.
If it has '_' or '-' character in it then you should use  and put the name in it (for example: [DB_server] if the machine name is DB_server.
Below is the sample syntax.
osql -U sa -P test -n -Q "BACKUP DATABASE [epo4_test-server] TO DISK = 'c:\msdebackup.bak' WITH INIT,SKIP"
I found an old KB article, KB#:KB59562 (https://kc.mcafee.com/corporate/index?page=content&id=KB59562&actp=search&viewlo cale=en_US&searchid=1287202364478).
Message was edited by: Hem Bihari on 10/15/10 11:20:51 PM CDT
Thanks, I'll try it.