Using a sub Contact Folder in Word Mail Merge

Advise please.

I use Outlook 2003 as part of my Office Suite 2003. I have Windows XP Home
with Service Pack 2.

One of my Contact categories is Christmas Card and I have copied all
contacts who fall into this category in a contact sub folder called Christmas
Card.

To print off labels to all those getting a Christmas Card I go to Word /
Tools / Mail Merge and set up the labels. However, when I click the “Select
from Outlook Contacts� and “choose Contacts Folder� I only see the folder
containing all my contacts. The Christmas Card sub folder is not shown.

Therefore, my question is “how do I obtain my sub folder called Christmas
Card?�