Hi jpinto1167,
If a Word file has an external link to another file, the link will be in one of the following fields:
RD
LINK
INCLUDE *
INCLUDEPICTURE
INCLUDETEXT
IMPORT *
HYPERLINK
* These are mentioned only for backwards compatability - they have been superceded by other fields in the list.
Other embedded objects (eg Excel workbooks) will be contained in an EMBED field.
You can test for any/all of these without opening the document in Word, by using a script that reads the file in text form. Note, though, that you'll likely also pick up HYPERLINK fields that only act internally to the document and that some of the field names might be used in contexts other than for fields.
Cheers