Excel macro to merge data from 1 csv file into another

Need an excel macro to export data from 1 shopping cart system to another. The csv output of cart 1 uses multiple rows for orders that consist of multiple items using the same order number more than once. The csv input for cart 2 requires multiple colums for orders that have more than one item and uses the order number only once. Also in cart system 2 the order specific values (sku/qty/amount) should merge into a single field. an example is attached.