txt_Current.Text = DirectCast(grid_Items.Rows(0).Cells("ColumnNameOrIndex").Value, String)
Sure, this is untested, but it looks like this :
VB.NET:txt_Current.Text = DirectCast(grid_Items.Rows(0).Cells("ColumnNameOrIndex").Value, String)
You must specify the row by index first (or use grid_Items.CurrentRow to get the currently active row), then the cell by using the column's name or index. This code must be surrounded by proper validation in case the cell's value is DBNULL as BDNULL cannot be cast to String.