Semianalytic function in Simulink

Hi,

I am working on BER calculation for OFDM in simulink. For some SNR's the value of BER is below 10^-6 and are not displayed in semilog graph.

I found that in .m scripts we can use semianalytic function to plot the values less than 10^-6, is there any similar function in simulink or any other method where i can plot these values.

Thanking in advance.