Is it possible to reference PCM_Rule as a source dimension in an allocation rule?

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Hi. I have a custom calc rule that moves dollars from multiple markets to a single market prior to allocating the dollars. I would like to use the dollars from that single market as my allocation rule source, but I'm not able to select the PCM_Rule associated with it. So, when I run the allocation, the amount allocated is the market's dollars from PCM_NoRule PLUS the market's dollars from the PCM_Rule associated with the custom calc rule.

Am I missing a step or is there a better way to accomplish this? My initial thought is to use the Indicator dimension but am interested in feedback.