How to create url link column in sublist?

Hi ,
How to Create sublist link columns through SuiteScript?
I have created a sublist with few column. in which one column is url type.

 var col = sublist.addField('custpage_sublist_url', 'url', 'Link',null);    for(var k=1;k<5;k++)  {  sublist.setLineItemValue('custpage_sublist_url', k , "http://www.netsuite.com");  col.setLinkText('Netsuite'+k);  } 

works!! but link text is not unique. I'm getting the

Netsuite4

in all sublist line. how can i get line based links. I mean each link should be unique with text.

I searched NS help center, in portlet there is something similar to this

 var col = portlet.addColumn('tranid','text', 'Number', 'LEFT');      col.setURL(nlapiResolveURL('RECORD','estimate'));      col.addParamToURL('id','id', true);