jQuery Grid Plugin - jqGrid

Hello,

I have some columns in the colModel that I need pass to the handler in the POST when the row is expanding and calling new data.

How can I do this without modify the setGridParam in grid.treegrid.js? 

I know jQuery(”#grid_id”).setPostData( newdata) and jQuery(”#grid_id”).appendPostData( newdata)

but the problem is how can I access the value in a column and put in the setPostData… something like this.column or similar….??

Thanks in advance

P.d: sorry for my Google-English…