Okay, I have to admit you have me stumped on the "CP" abbreviation. I know I'm going to pop myself on the head when I hear what it is, but I can't work it out.
I can answer your question in general terms, though.
In cases of dinner shows like Hoop-Dee-Doo and Spirit of Aloha, you simply need to tell the reservationist that you'll be on the
Disney Dining Plan. They'll still take your credit card information, but your card will only be charged if you are a no-show or cancel with less than 48 hour notice.
The same holds true for restaurants that require a guarantee or pre-purchase, such as Cinderella's Royal Table or the Fantasmic Dinner Packages. Tell them you'll be on the dining plan. They'll take the card number, but won't charge it.
If you change your mind after the fact, you can still pay out of pocket when you get there.