Row should selected, when user select on column

Hi All,

I have requirement, That in normal table have 10 columns and 10 rows. when out put by default first row is selected.

when user need to change on the 3rd column of the drop down on that time it should select on that particular row.

For that i wrote some sample code

  data lo_nd_itab type ref to if_wd_context_node.
  data lo_el_itab type ref to if_wd_context_element.
  data ls_itab type wd_this->element_itab.
*   navigate from <CONTEXT> to <ITAB> via lead selection
  lo_nd_itab = wd_context->get_child_node( name = wd_this->wdctx_itab ).

  data: lv_index type i.
  clear: lv_index.
  data lr_element type ref to if_wd_context_element.
  lr_element = wdevent->get_context_element('CONTEXT_ELEMENT').
  lv_index = lr_element->get_index( ).
  lo_nd_itab->set_lead_selection_index( lv_index ).

This code is working when i choose the column and press enter itself only this code is working, But i need when user select the column itself only on that time that row should be select. please guide me.

please refer the below screen shot for reference.

Thanks in Advance,

Amirineni Sravan.