Update Hidden row from seach/filter

valter479

I want to update/get data from row hidden by the search/filter.
I try to use the fnGetPosition to get the rowIndex from the element but the element it is not found; I believe datatables removes row instead of hiding them when you search/filter for a keyword, but i could be wrong.

Example;
var elem = document.getElementById("rowID");
console.log(elem); //displays null
var aPos = oTable.fnGetPosition( elem );