You would need code to bring across just the rows containing Company a, but
you can do a few things to show just Company a results

1) Copy the data to Sheet 2 and filter it (Data>Filter>Auto Filter)
2) Build a pivot table on sheet 2 from the data on sheet 1 and use Company
as a page/report field
3) Use the subtotal functionality (Data>Subtotals...) if you want to show
the data for the companies, with a total amount at the bottom. This also
'groups' the data

Let us know if this works for you, or if you want the code option