I know this is an ancient thread...but here goes for anyone interested in adding this to their AW2k.

What I have done is added this to the 'Auction Lot Information' section of an email template. (I usually send it with the 'Shipping Notification' email).

http://cgi2.ebay.com/aw-cgi/eBayISAPI.dll?LeaveFeedbackShow&useridto=<#SellerUserID>&useridfrom=<#BuyerUserID>&item=<#AuctionID>