pBlazSim Picoblaze simulator - Trouble Getting Started
The IDE is just a very simple bit of software to write the code in, and do some very basic testing - I an not aware of any automation features for pBlazeIDE which is what have been using, but according to trayres you can write scripts for pBlazSIM to control the I/O (not pBlazeIDE which is a different tool), so I'd check this out. For the complete picture you really have to simulate it in ISim (or ModelSim or whatever you are using) and use your testbench to drive the inputs.    

I just point the output of the Picoblaze IDE to generate the files in the Xilinx project folder (so it overwrites the old version automatically), then you can make a change, compile and simulate quickly.