Answering my own question for the benefit of others:
grid.CurrentCell = row.Cells[0] (or any other cell in the desired row)
Background:
I have a control - a very fancy treeview as it happens - that does NOT support databinding. I want to leverage the considerable benefits of the C1DataExtender plumming.
Solution:
I made a UserControl with my fancy treeview and an invisible DataGridView bound to my DataViewSet. On the DataBindingComplete event I read the rows of the grid to populate my fancy tree. Conversely, on the NodeSelected event of the tree, I make the corresponding row in the grid current.
Presto. Almost no code.
Hope this helps one or two people.
Amos Wittenberg