Originally Posted by
BlackBox
You might instead try using simple MText for your index, and then insert a Field for each component of your Sheet Set; Selecting 'SheetSet' for the Field Category, and Field Names, then in the middle Sheet Set pane, expand your target Sheet Set (if more than one are open), at which point depending on how you've organized your Sheet Set's Subsets & drawings, you'd either select the applicable Subset and Format casing, or the Drawing itself and the appropriate Property to populate your Index.
Then for items not included in your Sheet Set (like the 3rd party PDFs), you simply add a line of text as needed.
HTH