Is there a way to escape spaces in dynamically built member names in Business Rules?

Working on enhancing a legacy (Classic) Planning application and I am running into an issue with (Calculation Manager) Business Rules, with spaces in some member names. Even though I wish that these 'names' were actually Aliases and that the names didn't have spaces in them, changing this now will require a major re-architecture of the existing solution, which is outside the scope of what I am doing.

The scenario is - there is an Org (Entity) dimension, and a custom dimension that is essentially an InterOrg (IO), with the members in the IO dimension being of the same name as a subset of the Orgs, with 'IO_' prefix. The rule is attempting to perform something like this: