How to programmatically select a row in a multi-column list box?

I know the correct way of getting the selected row is by iterating over dialog.store()[itemId].aRows and finding the row that has the "Select" property set. So I tried programmatically iterating over the rows and setting the "Select" property to true for the row I want to select but it doesn't seem to visually select the row even after calling dialog.load({ itemId: data });