You can use the sim command to simulate the model from a start time, to a stop time and with a time step. Eg:- If your simulation time is 20 sec wherein, the first half is run with 1e-13 and the second with 1e-12 step size.
>>a=sim('try1','StartTime','0','StopTime','10','FixedStep','1e-13');
>>b=sim('try1','StartTime','10+0.1','StopTime','20','FixedStep','1e-12');
Combined outputs of a and b will give you the desired outputs. Change the #points to time and you will be able to use the code.
