Position DataGridViewComboBoxColumn's position

我想问，我如何具体地将DataGridViewComboBoxColumn 's放置到特定列?当前生成的DataGridViewComboBoxColumn位于最后一列。

DataGridViewComboBoxColumn cmb = new DataGridViewComboBoxColumn();
cmb.HeaderText = "Select Data";
cmb.Name = "cmb";
cmb.
//cmb.MaxDropDownItems = 4;
for (listItem = 0; listItem < dtLstItem.Rows.Count; listItem++)
{
    cmb.Items.Add(dtLstItem.Rows[listItem][1]);
}
dtgPo.Columns.Add(cmb);