Are you thinking something simple along the lines of storing an enum that contains the current state of the order? If so, you could define a column of type int in the database and then map to an enum like this:
Code:
<property name="Status" column="Status" type="MobysThinkTank.mobyProject.IssueStatus, mobyProject"/>
If you have something more complicated in mind, then it might help to first talk about how you envision storing the data. Figuring out the mappings comes secondary to first understanding how you want to interact, and then store, the data.