Custom attributes in IDM Entitlement Collector

Hi,
is it possible to add custom attributes to request from a target system via IDM Entitlement Collector?

Example:

  1. Setup AD via AD-driver with IDM
  2. create a few users
  3. set postalCode in AD on the users
  4. collect users in IG using the IDM Entitlement Account Collector

Now add postalCode to the collector. How to do this?

I have played with query-extensions in IDM, I can see the attribute is requested via the AD-driver but it is not showing up in IG.

regards
Daniel