The order that the expressions will appear when you save them to a Library is by that number that's in the upper left hand corner of an expression in the Expression Selection Dialogue box. That number, essentially, represents chronologically when an expression was made. So for them to appear in the order you want, they would have to be created in that order.
However, the hotkey assignments should copy through a library just fine, so if you assign a key to them (like "4" is assigned to "f" and "e" is assigned to "accel."), then the order doesn't matter (unless you have a BUNCH of expressions to copy over).