How to dynamically change the header text in OLAP Grid?

this.OlapClient1.OlapGrid.RowBound += OlapGrid_RowBound;
void OlapGrid_RowBound(object sender, RowBoundEventArgs e)
{
    if (string.IsNullOrWhiteSpace(e.GridRow.Cells[0].Text))
        e.GridRow.Cells[0].Text = "HeaderText";
}

Private Me.OlapClient1.OlapGrid.RowBound += OlapGrid_RowBound
Private Sub OlapGrid_RowBound(ByVal sender As Object, ByVal e As RowBoundEventArgs)
 If String.IsNullOrWhiteSpace(e.GridRow.Cells(0).Text) Then
  e.GridRow.Cells(0).Text = "HeaderText"
 End If
End Sub