I assume you have set up all the IMAP account info? (Like IMAP server = mail and SMTP server is mail and your account info from the server)
I use Outlook but think it'll be the same for Xpress. Click on the inbox so you are not in the overview page or calender or what ever. Then Extra->IMAP-maps->
You now get a popup window with the button query in it, press it and you should see all the IMAP maps it can find for you belonging to the IMAP account you created. The ones you have allready been subscribed to have a folder in front of them. Click on the map you want to subscribe to and press the subscribe button.
Now your outlook should have access. It doesn't display it yet but its there in the maplist you can select it there or make a shortcut.
Are you sure this is what you were looking for. I suspect its not but let me know if you figure it out.
regards,
Jan