asterisk users - Aug 2008 - How to create a user that uses mISDN using Asterisk GUI

Hi list.

Asterisk GUI (current version) does include the menu required for setting up
the mISDN Trunks ("mISDN Config"). But how about using those.
Currently that
seems not to be supported by Asterisk GUI or did I miss something? 

Whilst adding a new user extension I may select SIP, IAX and Analog
"Technology". "mISDN" is not an option that may be selected.
Is the only way
to use mISDN to make the required changes manually within the coresponding
conf files?

Best regards,

Klaus