…and it works fine but I want to supply another calculated property that then does a lookup for that EmailAddress and displays the displayName of the individual, if exists (because some are DL’s).
You can put any code you want into the Expression script block for a custom property. Whatever that code spits to the pipeline is what goes into the property value. So I suppose you’d do another Get-ADUser call…?
By using the below you can get what you need.There is no need for any expression. I don’t understand the need of using expression on EmailAddress property, other than just renaming the property.
More properly and for faster results instead of taking all properties of the users and selecting the one you need, It should be better to get only those properties. Check below: