How can you set Freight Terms to "No Charge" when order total is "0"?

We have a requirement to set the Freight Terms to "No Charge" if we are send the customer product at no change (order total = 0).  The intent is not to charge the customer for freight if we are sending them product at no charge as well. 

We have tried using the Pricing Promotional modifier functionality to perform a Terms Substitution with the line qualifying value of Context = Volume, Qualifier Attribute = Order Amount and Value From = 0.  This this setup we cannot get the order header or line Freight Terms to update to "No Charge".

Any thoughts on how this can be accomplished?