Yes I do, but you need to have an outlook first, and then install this outlook add-in, evo collaborator for outlook, with this add-in, you can sync both icloud and gmail calendars with outlook, once you have them synchronized to outlook, there is a function in this software called "browse caldav" and you use this function, select icloud account as source account, select the appointments you want to transfer, and click the "CLOUD TO CLOUD copy" button and you can then select your gmail account as the destination, now you can copy appointments from icloud to gmail directly over the air.
of course I will suggest you to practice with a few items first, and make sure it works fine then do more copies.
there is actually a tutorial here but I can not post link. so please copy and paste the url to a browser and check how to do it.
outlookandmacosxserver.blogspot.tw/2014/05/synchronize-your-icloud-andor-carddav.html