Getting a GridViewRow bound item?

In c# you can get the backing data bound member of a DGV using this
C# Code:
DataGridViewRow dgvRow = dataGridView1.Rows[rowNum];
object boundItem = dgvRow.DataBoundItem;
Is there any such way to do this using an ASP.net GridView that has a data table as its data source?

I have a data table with about 20 fields and I only need to show about 10 of them, but I need the other 10 for back ground calculations and file paths and such.

So far all I've figured out is to create Grid columns for everything, then hide the columns I don't want to show. I would rather not even make those hidden columns if I can get to the hidden data directly.
Thanks for looking
Kevin