global changes of varients i.c. price & weight on specific main category when product has several options and variables

We have a major category – Custom Bulletin Boards. Each product has options for size, ribbon color, etc. Each Option, Size, has four variables for weight, based on the size of the board they order. We have upgraded our product and need to change the weight of each weight variable for each product. We also need to change the price. Tho we know we can export and inport back, it appears that this is only for all products and doesn't include the variable for only the main category, Custom Bulletin Boards. Can anyone help me before we have to manually change 550 listings. Thanks so much. Diana