You could use a field coded as:
{IF{REF INT}= "Error!*" "" { REF INT}}
You probably don't need the \* MERGEFORMAT switch and the \h switch won't work inside another field.

Note: The field brace pairs (i.e. '{ }') for the above example are all created in the document itself, via Ctrl-F9 (Cmd-F9 on a Mac); you can't simply type them or copy & paste them from this message. Nor is it practical to add them via any of the standard Word dialogues.

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