Rollover of Users in AD

I have more than 3000 students in my Windows 2000 AD and they are grouped in years (e.g. grade1 or year 1). In the next school year I need to rollover the students so that the year 1 student will be transferred to year 2; and year 2 to year 3; and so on.

Each year group is in different container and each container has a different policy settings.

Can anybody help me automate the rollover without typing the students name again?