How to update a single field in Word macro

Question

Hello,
I am trying to create an AutoOpen() macro that will update the file name and path when user opens in a Word document, but I can't seem to find anything explaining how to update a single field, specifically the {FILENAME \p} field.  There
are other fields in the document, so I do not want to update all the fields.  Most of the links I found only explain how to update ALL fields. Can somebody please tell me how I can update only the filename and path field using an autoopen macro?
Thank you

Answer 1

Stefan's response is correct.
Here is a macro that should update only filename fields.
Sub FileNameFieldUpdateAllStory()
' Written by Charles Kyle Kenyon 15 November 2001 - modified for filename 10 Sept 2014
' repaired by Jezebel
' All Story Field Updater - Filename fields
Dim oField As Field
Dim oStory As Range
' On Error Resume Next
For Each oStory In ActiveDocument.StoryRanges
' This goes into headers and footers as well as the regular document
Do
For Each oField In oStory.Fields
If oField.Type = wdFieldFileName Then
oField.Update
End If
Next oField
Set oStory = oStory.NextStoryRange
Loop Until oStory Is Nothing
Next oStory
End Sub
See Installing Macros for help in using this.
Charles Kenyon Madison, WI