software

I have spent several days digging in the help documentation but I am just not
getting it.....
I have a sheet that contains 30 days of data from a select statement import,
after tailoring with macros I end up with:
Data varies between 6 - 8 rows of data per day date. I want to sum one
column(C) per row of data per date(A) into a daily total in Column D in an
automated routine. Any suggestions?.
A B C
D
1/2/06COLOC_TAPEPOOL415,865,778,739
1/2/06ENT_TAPEPOOL225,837,650,638 sum total for day here
1/3/06(DIFFERENTIAL)26,006,331,392
1/3/06GENTAPEPOOL89,365,376,624
1/3/06(DIFFERENTIAL)213,924,297,728
1/3/06(DIFFERENTIAL)380,020,412,416 sum total for day here
1/4/06ENT_ARCH_TAPEPOOL0
1/4/06COLOC_TAPEPOOL351,722,484,436 sum total for day here

Thanks - Thane