This is all I saw in my Help for Word 2003. Have you tried MS Excel? It may be better for your purposes since you can create lists and filters.

Add, remove, or change the order of items in a drop-down list

1. Open the template (template: A file or files that contain the structure and tools for shaping such elements as the style and page layout of finished files. For example, Word templates can shape a single document, and FrontPage templates can shape an entire Web site.) that contains the form (form: A document that contains fill-in blanks, or form fields, in which you enter information. For example, you can create an online registration form in Microsoft Word that uses drop-down lists from which users can select entries.) you want to change.

2. Remove protection from the form template by clicking Protect Form on the Forms toolbar (toolbar: A bar with buttons and options that you use to carry out commands. To display a toolbar, press ALT and then SHIFT+F10.).

3. Double-click the drop-down form field (form field: In a form, a location where a particular type of data, such as a name or address, is stored.) you want to change.

4. Do any one of the following, and then click OK:

• To add an item, type the name of the item in the Drop-down item box, and then click Add.
• To delete an item, click the item in the Items in drop-down list box, and then click Remove.
• To move an item, click the item in the Items in drop-down list box, and then click the Move arrow buttons.

5. If you want to clear any information that you might have entered while working on the form, click Reset Form Fields on the Forms toolbar.

6. Protect the form by clicking Protect Form on the Forms toolbar.

Note The first item in the Items in drop-down list box is the one that appears by default in the drop-down list. To move the most frequently selected item to the first position, use the Move arrow buttons.