Millisecond Forums

I am trying to create a batch file in which there are 3 separate experiments where a participant completes a specific experiment based on subject number. Each subject will complete every experiment separately over the course of 3 weeks. The idea is that individuals will enter 0, 1, or 2 before their subject number such that 0001-0999 would be assigned to experiment 1 for week 1, 1001-1999 would be assigned to experiment 2 for week 2, etc. However, I am having trouble defining subject ranges in this way without getting an error. Is it possible to define subject ranges in such a way? Using the "1 of 2" language/odd numbered participants would not work as there are 3 experiments and each person needs to complete each one over time. Perhaps there is an alternative?