QP: Limit Bases on Pricing Modifiers

Hello Advanced Pricing gurus,

I've created a new modifier line for a new promotion the business group is releasing to the market within the next week.  The promotional campaign involves a customer calling in with a promotion code (i.e. ABC150) to receive a 150.00 off a single order.  The order can have 1 or more lines but will only get a maximum of 150.00.  I have this all worked out using a modifier type of "Price Break Header", "Group of Lines" for the level, etc.  All is good; however, the business group also has a requirement to ensure a given customer can only use the promo code only once.