I assume you are asking to auto scroll a cell content in data grid, just like a marquee tag does in plain HTML. This can be achieved by modifying cell content in grid's ItemDataBound event (considering you are using ASP.Net native DataGrid control)
private void grdYourGrid_ItemDataBound(object sender, System.Web.UI.WebControls.DataGridItemEventArgs e)
{
if(e.Item.ItemType != ListItemType.Header && e.Item.ItemType != ListItemType.Footer)
{
e.Cells[0].Text = "<MARQUEE>" + e.Cells[0].Text + "</MARQUEE>"
}
}