Share 'Calculate certain object out of other objects?'

Hi I'm doing a solar radiation analysis of a city centre with GECO, there are many builings. And I just want to calcalate the red one( in pic),  but when I use the EcoSolCal component to do objects calculate, it calculate all the buildings.  I know that in Ecotect there is a "Only use selected objects" option, is there a way to do the same with GECO?  Because I'm going to do a revolutionary sel…