Assigning individual activities for students

I wish there was some way to assign seperate activities to an individual student without putting them in a seperate city or class. I have am the computer lab teacher and I have classes with student who are lower level learners in them and when I go through the instructions on how to login with a particular class my lower level students want to login the way I just taught the class as a whole. This causes a problem because then I have to show them how to login a different way which makes them stand out, which isn't good for their self-esteem. I'd really rather keep them in the same class or city as the other students and be able to modify there work.