Add Node to post processing feed

I like to organize my feeds by node. All my power feeds are under the W: node. While all my kWh feeds are in a kWh: node.

I want to post process two feeds and add them together into a summation feed. The 2 feeds are in my W: node and I’d like the new feed to also be in the W: node.
Is there anyway to run a post process command and specify the node for the new feed?

Thanks so very much!