summing sets of numbers and adding ablank row

I have a very large DB that needs to be automated. There are blank rows between each set of data. I need a MACRO that will sum the numbers in one of the columns in a data set and then insert another blank row under it, then move down the column repeating the process. The data sets are of varying sizes and there are lots of them. I would also like to copy the sums to another sheet.

The Sub function is not feasible because of the format of the file and the additional steps that I require.