How do I get a measure amount to sum differently than another

Here is my problem I have a table that has two measures, for one measure I need to sum everything in that field for the other measure I need to find the max date a combination of 2 fields.

Here is how the table looks and what I need

date1            date2        amt1     amt2

20020522  20020619  45.60  45.60   x

20020522  20020619  43.49  43.49   x

20020522  20070921  11.83  9.69

20020522  20071107  11.83  -9.69

20020522  20080215  11.83  0.00    x

 total                                 100.92   89.09

I need to sum all of the amounts in the amt2 column, and I only need the max dates in the amt1 column (see x for the ones I need).  Not sure how to do this one and I need the detail to show for amt2 is it doable?  I am currently using Microsoft SQL 2008 R2.

Antonio