Crash,
You can build this on your own, if you look in the help file in AutoCAD Electrical and type in PLC. this will give you a pretty good overview of how to create your new PLC Module.
For a brief over view, you are going to need a .dat file that will contain a stack sequence. this stack sequence consists of a list of blocks 1-6. blocks 1-6 are what it takes to parametrically build each plc.
if you have anymore questions let me know