Accessing ItemRenderer in AdvancedDataGrid Flex / AS3?

Question

i have XMLList data which is used for advanceddatagird dataprovide(by converting it to hierarchal data ), the advanceddatagrid consist of 2 columns,i want to access the ItemRenderer of 2nd colomn (customized item rendrer) by giving the item. i can get the itemRendrer bu using

var Obj:Object = itemToItemRenderer(item);

i cant understand that obj is IListItemRendrer, but in 2nd colomn i have used the renderer named "ProcessFLowRendrer"? can you tell me how i can access the rendrer of 2nd column, by item not by index ?