Saving Old Permalink Structure While Using New One

hi, i want to change my permalink structure, but while changing, i don’t want the old url structure to get lost that are indexed for nearly a 1,56 years. is that possible to save old structure while using the new one

(p.s: i know it’ll make issues with supercache, but it is ok if the old structure wouldn’t be cached anymore)

thanks for any infos 🙂