A bus of netgroups

Hi, 

Is it possible to make a bus out of several netgroups in Capture? 
I have created different netgroups named CH0, CH1, CH2 .. CH19. 

Can I connect them together as a bus named "CH[0..19]? 

When I tried this solution I get the DRC error "net has less than two connections" for the nets that are defined inside the respective netgroups.