Firstly, there is no need to use field coding for this - the VBA code in:
Dependent Text Content Controls
Multiple entries in dropdown lists
shows how to make those updates directly from the relevant content control.

Second, your use of fields means you'd have to add additional code to the ContentControlOnExit macro to get them to update.

Third, even if field coding were used, you don't need the \* MERGEFORMAT switches.

Fourth, in a document accessible for editing, there's a very real risk of someone overtyping/deleting the field coding; a content control, by comparison, can be protected against both.

Finally, as you why you're getting that particular error, that may be because you've typed some of the braces instead of creating them via Ctrl-F9 or via Insert|Cross-reference. There should also be a space between your "" sets.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]