WPA2-EAP: get logged on user

I’m using CapsMan to manage some ~30 AP which provide authentication (802.1x WPA2-EAP) against a Windows 2012 NPS (Radius-Server).
Everything is working fine - you see the clients in the registration tab coming on and off.

Now is there a way to display the username which was used in the registration table (or somewhere else)?

I know you can display a comment besides each client which can be set by sending the radius attribute Mikrotik-Wireless-Comment. This basically works but I’m limited to hardcoded values. At least to my knowledge with microsofts NPS-Server. So all I managed to do so far has been to set the comment field beside each client to “WiFiBasic” and “WiFiOpen” - depending to which ActiveDirectory-Group the users belong.

There has to be a better way. Maybe there are some variables in Microsofts NPS so that you can create a network policy with something like Mikrotik-Wireless-Comment=%username%.
Or routerOS has some hidden function. If you look in mikrotiks log you can see the access-request with the username going out to the radius-server and and access-accept (or reject) coming back. So the information is basically there.

tldr;
I’d like to see each logged on user to my network in a WPA2-EAP scenario. Just the way you can see each user under the hotspot->active tab if you use WPA2 with a Hotspot and radius authentification.

Suggestions please.
TIA Christian