You should have no problem doing that with the AccelStepper library - what have you tried? What happened?
Really, if you are serious about getting help you need to tell us a lot more about your project
How many stepper motors?
What are the motors being used for?
Is it essential that the motors move in a co-ordinated manner - for example motorB moves 123 steps in the same time that motorA moves 837 steps?
Post a link to the datasheet for your stepper motors.