This is not appropriate for kittens or cats. They cannot digest cows milk, and not only will it probably upset their stomachs, it will most likely give them diahrreah, which can dehydrate small kittens and make them very ill very quickly.
Corn flakes are made for humans, not for cats.
Even so,
cats are carnivores. They were not meant to eat corn flakes. They are meant to eat meat, and they need it to thrive. Meat, not fish, which should only be fed at a minimum.
Foods made for humans, especially prepared food are lacking in certain minerals and vitamins that cats need, and the lack of them can cause things like blindness and even worse. Same reason you can't feed a cat dog food.
You said it's almost impossible, can you stock up? There are plenty of on-line sites where you can order bags of decent kitten and cat food mail order.
If you absolutely can't find cat food and want to feed your kittens and cats a homemade diet, here are a few links to websites with recipes for homemade cat food. Please read them, because they explain exactly what cats need to survive and thrive. You can do a lot of damage to your kittens if you don't give them the right nutrients, which in the wild they would get by eating live prey.
http://www.ehow.com/how_12698_make-homemade-cat.html
This site has quite a few recipes, so scroll down the whole site, which has great information
http://www.stretcher.com/stories/03/03jan27a.cfm
This site has a few recipes for home made cat treats, biscuits and cookies:
http://www.cdkitchen.com/recipes/cat/1231/0.shtml
PS: Cornflakes and milk aren't all that healthy for human babies either, the corn flakes are highly processed and high in sugar.