Which version of SQL server are you using?
On SQL Server 2008 you can rollup any column with partitioning.
select
sum(aggregation_field) over (partition by GroupingField)
,otherfield2
,otherfield2
from
dbo.table
You can group by another field or not group at all.
Note that with this you will get the sum of <aggregation_field> in every row.