Yigang
To implement z^-200 in Simulation, you can use the Transfer Function block and enter 1 on the 200th position of the denominator, the rest is zero. The Editor for TF has indication only until 99, but if you keep scrolling to the right, you should be able to set it properly.
Let me know if you can't do this.
Barp - Control, Simulation, RTT and HIL - National Instruments