Sara - now I understand - you want to pass a variable into the conditional formatting
You can check the Design Studio Roadmap here https://websmp203.sap-ag.de/~sapidb/011000358700000390622012D.pdf but I don't see this spelled out or mentioned.
I don't know if this could be accomplished by SDK since I haven't developed an SDK for Design Studio
Another alternative is to add this as a suggestion to Idea Place at ideas.sap.com - I hadn't considered doing what you are suggesting, but it is interesting.