In FoxyPreviewer, that's really very very simple !
- Select the field that you want to justify
- Double-click that field to access the properties dialog
- Select the "Other" Tab
- Click "Edit User Data" button
- Add the "<FJ>" tag in the textbox
That simple !
When you run your report, that field will appear justified.
This setting works also when you export your report to PDF, RTF and HTML!