Hi Pam,
I would think you could take crisp sugar cookies (store bought)and process just like you would do when taking whole graham crackers to make your own crumbs. You may have to use a little less butter than the original recipe calls for as sugar cookie crumbs are a bit more tender than graham cracker crumbs. I hope this helps. Let us know if this is an alternative for using the graham cracker crust!
Take Care!
Kate