This is what I have done. However, you still have the risk of collisions. Depending on the context, like i did a small test and permuted all letters a-z and n

This is what I have done. However, you still have the risk of collisions. Depending on the context, like i did a small test and permuted all letters a-z and numbers and there are no collisions. However, changing a-z to A-Z resulted in many(may need to check code). However, this allows for a 5 character command switch.