Update multiple cfgrids using flash remoting

I'm working on an application to allow people to enter their paid time off and because of the specs of the project I need to have a cfgrid for each month, so 12 grids. I have all of the remoting working if I hard code the grid names, but I also am able to pass the grid name through the cfcs and display it via an alert on the response handlers. What I cannot get to work is to create a variable of type mx.controls.DataGrid and assign the grid name to it. I'm assuming this is because the grid name is a string and not a data grid object.

Does anyone know how to dynamically reference a data grids in ActionScript? I'll post the code below.

<!--- handle update response - This code does not update the grid. The value of results.gridName is 'AugPTO' --->
responseHandler.updatePTO_Result = function ( results:Object):Void {

if (results.status) {
var item:Object = results.item;
alert(results.gridName);
var grid:mx.controls.DataGrid = results.gridName;
var index:Number = _root.findItem(grid,'PTOID',results.PTOID);
grid.replaceItemAt(index,item);
}
mx.managers.CursorManager.removeBusyCursor();

alert(results.message);
}

<!--- handle update response - This code does update the grid. AugPTO is the name of the grid for August. --->
responseHandler.updatePTO_Result = function ( results:Object):Void {

if (results.status) {
var item:Object = results.item;
var index:Number = _root.findItem(AugPTO,'PTOID',results.PTOID);
AugPTO.replaceItemAt(index,item);
}
mx.managers.CursorManager.removeBusyCursor();

alert(results.message);
}

Any ideas?

Thanks,
Dan

p.s. I've followed to Real Estate example from CFDJ to get this far, so if you are familiar with that app mine is pretty similar.