Change a string to a variable?

Slight problem here, hope this is even possible…
I got this :


columns = new Array(bg_ID, bg_NAME, bg_DIR);
for(i=0;i<result.items.length;i++){
	for(ii=0;ii<columns.length;ii++){
	 itemToAdd = result.items*.columns[ii];
	 trace(itemToAdd);
	}
 }

The problem is,
result.items*.bg_ID is the actual container which holds the data.
However i want to fill in bg_ID, bg_NAME…etc… dynamically.

so basically the content of
itemToAdd = result.items*.columns[0]
should refer to the content of
itemToAdd = result.items*.bg_ID

but this is not working… but if i want to obtain the correct data in
var itemToAdd i have to use result.items*.bg_ID?
or is there a way where i add the expression (result.items*) and the string from the columns array together then flash will read this as a container which holds data?

hope im clear
thx already