How to install/attach additional Simulink toolbox?

Hello.

I need to use fractional PID controller. It's not included to my Matlab. I downloaded "ninteger toolbox" with nintblocks and nipid code. How to attach/install it propertly to be visible in Simulink library and to be usefull?

Copying nipid block simulink reports an error:

Error evaluating parameter 'sys' in 'trs_cross_pid/Fractional PID/LTI block'

Caused by: Undefined function 'nipid' for input arguments of type 'double'.

It's no 'sys' parameter in this block, and an error doesn't occure with simple PID controller block embadded in Simulink.