Need assistance with creating a specific rule

Alright, I've used hashcat for a couple of years now but today I came across a situation where my normal tricks aren't going to work.

I know that all passwords follow this pattern: ?l?l?l?d?d?d?u?u?u?s?s?s

I also know that for each ?d that the ?s is the same key in the same order.

An example password would be:

aaa123AAA!@#

What would the best approach to this be with the information that I've given?

Thanks in advance!