Query Join Problem

Hi all,

I am trying to join two queries together, but the join is
on a normal field in one query to a calculated field in
another. The join is working fine, and I am pulling the
calculated field into the joined query. However, as I
have specified for the the join to take all the records
from one query and only those that match from the other,
rather than leaving the field blank the query is
inserting "#Error". I realise this is because it is a
calculated field, but how do I go about formatting the
field to pull as a blank rather than "#Error"? Any help
would be greatly appreciated.

Regards,
Tom