Then you have the containing calculation field wrong. I have used these methods and they work.
Alternative 1:
Use a copy of your document and use the macro on it. See what happens. It won't hurt.
Install/Employ VBA Procedures (Macros) by Greg Maxey, MVP
Alternative 2:
Otherwise, contact Greg directly and ask him what his fees are. I have used code that he has written for years with good results.