It is possible and it looks like you already applied it to those items. Did you want me to move them out of your sidecart and into your pending subscription order for this month?
Sorry for the confusion, after I submitted the order it no longer said anything about the rain18 code so I though it had gotten removed. But doing the math, I can see it is still there.
I just went to move them into the order but it looks like it has already shipped so I won't be able to merge them. Did you want them to stay in your sidecart for next month or ship out on their own right away?