How to use a timer to call a function, and assign it's output to a variable in the work space

Hello,

I'm a new user, and I want to use a timer to call a function, and take that function's output argument to the main code.

I'v tried the following code, but it only prints the output value to the screen. Am I using the correct timer format? Please help.

assignin('base','A',1);
t = timer('TimerFcn', '[A] =time( A )', ...
        'StartFcn', @(~,~)fprintf('AAA. %d \n',34)); % timer is defined
    fTime = now + 5/(3600*24); % Timer is set for 5 sec (in serial time)Matlab
    startat(t,fTime);
if A==2
    C=A*4
end

function [ A ] = time( A )
A=A+1;
end