How to replace null values by a string in a query?


I am using two queries Query 1 and 2 and the union of the two queries query 3 is used to build a crosstab. I have applied a detail filter to query 2 to return only null values for Sales Manager.

Now I want to replace these null values in the crosstab by the string ‘Orders without Sales Manager’. When I use the data format (custom) option to replace the null values it doesn’t seem to work. So is there any expression to return a string instead of null at the query level itself?