A Separate Oracle Database at work
In short, the answer to your questions is yes. However, I think you should bear in mind... 

Try to get a version of Oracle XE that is the same as your company's main database. 

You'll need to remember where your applications are configured to connect to and be careful to not inadvertently connect to a database you shouldn't, like the live or production database. Hopefully there will already be security in place to prevent you from doing this.

Also, keep in mind the limitations of XE:


  
  only use one CPU on a system
  use up to 1GB of RAM
  store up to 4GB of data
  11GB of data on 11.2
  
  
  The following database features are not supported:
  
  
  partitioned objects
  internal Java virtual machine (JVM)
  


I also wondered about possible licensing issues, but a quick Googling threw up these interesting posts...

Clarification on Oracle XE licensing - really free for any usage?

As well as the forum links in the above blog, I also found these:

oracle 10g XE in commercial enviroment

Oracle XE, is it really free for commercial use?