There is no way to do this through the Cite While You Write tools, but there is a workaround:
Go to the Tools menu > Change Database Sort Order.
Set the sort order to “User Def 1.”
Click Sort.
Click OK and Close the Sort.
Note: You can also click on the heading for User Def 1 column to sort by that field.
You can now use the “Generate from Reference List” command to create a bibliography from your database. Check the items you need if you do not need your whole database. Click the Tools menu > Bibliography > Generate from Reference List. Here you can define additional settings and set the Destination to File. This will allow you to create a formatted bibliography in the order sorted by the database.