Sum of data across multiple columns & rows based on Criteria

Maybe this will explain it a bit better. I have data across multiple rows and columns. Top row has unique criteria (codes/headers, if you will, in numerical format) across all columns. First column has numerical codes that may repeat in several rows. I need the formula to look at all columns and rows, find each instance of a specific code combination, and add up those cells. For example, look for 123 in the top row, and all instances of 567 in the first  column, and add all the cells where those intersect.