Does anyone have experience applying the “USGBC LEED 62MZCalc” spreadsheet for Indirect Evaporative Cooling (IDEC) systems?

Or, is there an alternate compliance path elected due to the significant differences as compared to ordinary air handling systems that return a large percentage of return (re-circulated) air?

We are challenged with how to correctly apply this spreadsheet for an IDEC system that runs, for most of the year, at 100% outside air. It would seem that there would be a special steps provided within this spreadsheet to consider IDEC systems since, looking from a broader perspective, it would seem intuitive that an IDEC system will much more than satisfy the ventilation requirements for 95% of the year.