Need a bit of code

Using Arduino Nano I need a bit of code that will run a stepper a number of steps when a pin is made high, to start me off

Have you tried the AccelStepper library in the arduino Playground? MotorControl section

Why ?

There's tons of tutorials online how to do this . Why are you posting here if you haven't tried anything yet ? We would be happy to help you learn but this isn't a program writing service. This is a help forum. You write the code and we help you with it. You have to make the first move. That's how it works. If you want someone to do your homework for you use another forum.