jQuery Grid Plugin - jqGrid

I need to get the cell object from one of my functions that only have the rowId and colId of the cell.

In other words, I need to get the cell object by using it's row and column indexes.

(Please note the NEED YOUR HELP ON HOW TO DO THIS bit in below code.)

What I do is, I generate below URL within my customFormatter at the loading time for each cell of some columns of my JQ grid.

function ViewColumnFormatter(cellvalue, options, rowObject) {

    if (options.colModel.commandCount > 1) 
    { 
         return "<a href='#' onclick='showContextMenu(" + options.rowId + ", " + options.pos + ", "" + options.colModel.menuName + """ + ", "" + options.colModel.gridName + "");'>" + cellvalue + "</a>";
    }

}

So when a user clicks on the link inside the cell at the run time then the script calls below javascript func.

function showContextMenu(rowId, colId, menuName, gridName) 
 {
      var gridCol = get column object by (rowId, colId)  << NEED YOUR HELP ON HOW TO DO THIS. >>
      $("#" + menuName).position({ my: "left+20 top+10", of: $(gridCol), collision: "fit" });
 }


All I want to do is to get hold of the cell Object by using the row and column index.
P.S. I deleted some of my code to avoid distractions so please ignore if you spot syntactical or other linguistic errors.
Please help...