IMO means "In My Opinion".
Yes, you can stop SQL with this dos command:
net stop sqlserver
But really, why do you want to do this? You've been given two options for backing up a system while it is running, and these are the only two options you will ever get support for.
As to it being "not good", well I can see how it would sound that way, but what you're asking is really something Veritas could never do in a way which is "technically" good.
Databases are complex systems, and to simply backup an in use file is almost guaranteed to produce an inconsistent file, even if an open file option did let you do it (Note: VSS is special).
Stopping the database might suit your needs, but very few people who have purchased backup systems such as Veritas want to then go back and use obsolete backup methods such as stopping services.
As suggested, either purchase the Veritas SQL Agent, or configure a "Database Maintenance Job" in the SQL Enterprise Manager to backup your database to a file every night, just before Veritas backs up your system. Those files will go to tape and you have a working backup.