Cannot implement a particular custom template file to a profile used in Civievet register form

Cannot specify a particular custom smarty template file to a profile which is displayed in Civievent registration form. CiviCRM can recognize path <custom_templates_folder>/CRM/UF/Form/Block.tpl, but not <custom_templates_folder>/CRM/UF/Form/< profile ID >/Block.tpl, whcih means it is not able to assign different custom template files to different civievents.