Hi Eduardo,

In pseudo-code then, you want to

1. Open all documents
2. Update all fields in every storyrange
3. Save Document
4. Close document

You can accomplish 1. by using the code in one of these two articles:
"How to read the filenames of all the files in a directory into an array" at
http://word.mvps.org/faqs/macrosvba/ReadFilesIntoArray.htm (you will use this
one if all the documents are in the same folder--no subfolders)

If, however, you do not have the documents in a single folder, but in a
"master" folder with several subfolders, then you will want to use the above
combined with the article "How to get the names of all the folders in the
folder tree, starting from a specified folder" at
http://word.mvps.org/faqs/macrosvba/ReadFoldersIntoArray.htm

This will certainly get you started. After that, you'll want to be able to
ACCESS every storyrange in the document. To do that, you can borrow a portion
of the code from the article "Using a macro to replace text where ever it
appears in a document including Headers, Footers, Textboxes, etc." at
http://word.mvps.org/FAQs/MacrosVBA/FindReplaceAllWithVBA.htm

Once you combine these, saving and closing is easy.

Hope this gets you started,

Dave