There is no Agent job monitor in SQL Express.

Here are some ways that can work as an alternatives::

1. Create ur own service(especially window service), that will take care of the scheduled backup by calling the backup sp.

2. use the following link if you can buy the 3rd party Agent utility: http://www.valesoftware.com/products-express-agent.php

3. Create your own agent by following this link:

http://www.codeproject.com/KB/database/SQLAgent.aspx

The better you can do is the point 1. and 3.