When using an MS Access database query as the data source to perform a Mail Merge in MS Word, wildcard characters (the asterisk) cannot be used in the criteria strings of the underlying query that provides the record data to Word.
There are two possible solutions for this issue.
Whenever possible, avoid the use of wildcard characters in the criteria strings by specifying allowed conditions explicitly. For example, retrieve the desired records by specifying the exact text phrases allowed in the criteria rows of the Access query.
Use an additional query to mask or hide the source query containing wildcard characters from Word. Assume that qryA contains at least one or more wildcard characters in its criteria rows. Create a new qryB that uses qryA as the sole data source for qryB, select all fields from qryA to be included, then specify qryB as the data source for the Word Mail Merge function. This allows the use of the wildcard character but makes it transparent to Word.