You may add an option to import items from a file. So there is just the need to copy with ssh in a file from the recipe and EasyList can import them easily.

Or, and here it's a bit "harder", knowing the ip of N900 in the w-lan, developing an app for Desktop that can send items to EasyList through udp protocol. No need to put a server just for that, there is QtNetwork module for this. Just an example, on the desktop app the user insert an item like "apple" and when he clicks on "add" the software send via udp/tcp the string to EasyList, and EasyList adds it to the current list.