Word has not got the method GetOpenFileName that can be used to let a user select a file name or a folder. You can use the user defined function below:

Function WordApplicationGetOpenFileName(FileFilter As String, _
    ReturnPath As Boolean, ReturnFile As Boolean) As String
' returns the folder and/or filename to a single user selected file
Dim strFileName As String, strPathName As String
    If Not ReturnPath And Not ReturnFile Then Exit Function
       If FileFilter = "" Then FileFilter = "*.*"
    With Application.Dialogs(wdDialogFileOpen)
        .Name = FileFilter
        On Error GoTo MultipleFilesSelected
        If .Display = -1 Then
            strFileName = .Name
        End If
        On Error GoTo 0
    End With
    On Error GoTo 0
    ' remove any "-characters
    If InStr(1, strFileName, " ", vbTextCompare) > 0 Then
        strFileName = Mid$(strFileName, 2, Len(strFileName) - 2)
    End If
    If ReturnPath Then
        strPathName = CurDir & Application.PathSeparator
    Else
        strPathName = ""
    End If
    If Not ReturnFile Then strFileName = ""
    WordApplicationGetOpenFileName = strPathName & strFileName
MultipleFilesSelected:
End Function