Hide/Show details in an Outline Group

I'm trying to create a simple two column cost summary in Excel 2007. Column
A has about 700 rows of Cost Item descriptions and Column B is where I want
to enter the costs associated with the Cost Item descriptions. The Cost
Items in Column A have been organized into Groups and Subgroups via
DataOutlineGroup. In reality, I will only enter costs in about 25 of the
700 rows available depending on the project needs. I'm looking to a way to
show only the rows that have costs entered but can't figure out how to do
this without showing the entire group. "Hiding" rows is an option but would
be pretty tedious. My Visual Basic skills are very limited but am open to
using it.
Thanks.