Table: Column lazy loading

Hi,

I am using Tree table to display my data. In my case certain columns data is coming from webservice response. If the response is slow it is taking some time to render the screen. I would like to do it dynamically to avoid delay in rendering the data. Means that first I want to render the screen with the available data and simultaneously I will call the webservice. As soon as I receive the data from webservice I have to show in the respective column data in screen with out refreshing the entire page.

Can you please guide me how to achieve this ? (possible with code samples)

Thanks and Regards
Uday