When EXECUTE macro option is selected:
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1. If you have a macro enabled document skip to point 4.
2. Open a blank Word document.
3. Save as Macro enabled Word document (*.dotm or *.dotm)
Let’s say you save with the name doc1.dotm

4. In this application click button "Macros" and open 
a macro enabled Word document (doc1.dotm or the name you have given to it).

5. If there are pre-existent macros in ThisDocument will appear in the textbox.
6. Add any new macro with one Document parameter as in:

    Sub DeleteSpellingErrors(doc As Document) 
        Dim cnt, i As Long
        Dim cur, Last As Range
        Do
            cnt = doc.Range.SpellingErrors.Count
            If cnt <= 0 Then Exit Do
            Set Last = doc.GoTo(What:=wdGoToSpellingError, Which:=wdGoToLast)
            Set cur = doc.GoTo(What:=wdGoToSpellingError, Which:=wdGoToFirst)
            For i = 1 To cnt
                cur.Select
                cur.Delete
                'Debug.Print cnt & " " & i
                Set cur = doc.GoTo(What:=wdGoToSpellingError, Which:=wdGoToNext)
                DoEvents
                i = i + 1
            Next
        Loop
 End  Sub

5. Clicking "Accept" will close the dialog and fill 
the combo box with the name of the macros.
6. Select a macro or type in the combo box.
7. On the right side of the form click the button "..." and browse 
to a folder containing the Word documents to which execute the macro.
8. Check subfolders if there are also documents contained in subfolders  to execute.
9. Click Start. 
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On the other hand, option 'DeleteSpellingErrors' will need 
a folder path with Word documents to which 
delete all the spelling errors.

======================================
 Advanced use.
 =============
You may employ extra parameters (up to 29 extra parameters, 
30 in total counting the always needed 'doc' parameter).
For example, if you add this macro to replace matching 
strings of 'str'contents by 'byStr' contents, you would 
type in the combo's text box: replace("he","Smith, John")
Note: you do not have to write 'doc' parameter, just the 
extra parameters.

Sub replace(doc As Document, str, byStr) ' here 'doc' is mandatory
    doc.Content.Select
    With Selection.Find
       .Forward = True
       .MatchCase = True
       .Text = str
       .Replacement.Text = byStr
       .Execute replace:=wdReplaceAll, Forward:=True, _
            Wrap:=wdFindContinue
    End With
End Sub