function output on callback

[Cora248]

Hi all,
I am rather new to using function handles, and I ran into a problem. Suppose I am defining a timer callback function, but it has output arguments. How can I get them from the function? I can't find it in the documentation.
The definition is for example
t=timer;
t.TimerFcn={@Callback1, arg1, arg2} % passing input args

How can I get access to the output arguments of Callback1, when the timer is running?
Thanks a lot