i was wondering if there is a way to assign a key to a specific command ex: z key
I know that they have special names ex. sKeyName_2B
All i need to know is the script command to allow me access something to use the command
like if i want to press the z key (nothing else is assigned to that key) and have it start a script
would that be possible

Well, you could set up an item that executes the given command whenever it's equipped, and then assign a quick key to it. Aside from that, the only way you'll be able to accomplish this is by using a script extender.