Hi,
This can't be done by default in HikaShop but thanks to some code editions this can be done.
You will have to edit the views "product / waitlist" to add the desired fields, edit the controller product to edit the MySQL query to add the informations in the columns (before that you have to update the table "#__hikashop_waitlist" to add the columns via phpMyAdmin). Then you will have to edit the view "product / waitlist" (backend template) to display the saved informations.
So it require php knowledges.