User-device mode, translating in extensions.conf?

When you are in user-device mode, how does the translate work from user to the device id in extensions.conf ?

exten => kenneth.datastruct,1,Dial(SIP/100);works

exten => kenneth.datastruct,1,Dial(SIP/200);doesn’t work

I want to use the 200 id which is a user id, but it doesn’t work. When i put 100 (=device id) it works.

How can I translate a userId to the device on which the user is logged into?

Try this: