I'm just trying to add an extra sku field to all products, which is not showed in frontend but searchable in backend. I mean users or guests wont be able to see this extra sku but i will be able to search the products by this field. still not solved.
Listed below are 2 of the several ways of accomplishing this. To answer this question will required writing too much code, so please choose a method and if you have any additional issue please ask a more specific question base on your choice.