How to extract signals in netgroup?

Hi, 

We collaborate schematic entry under OrCAD EDM environment. 

Our project contains FGPA, so that we have to use many of netgroups to tie many kind of signals, bus or scala.

By the way, when a designer1 modifed or add signal in netgroup, designer2 cannot know of whether it is modified or not, which results in error in the end.

If we can check netgroup modification by another designer, we can reduce the time requiring to check netgroup modification.

Is there any way for us to extract the list of netgroup or to know of netgroup modification in advance?

As far as I strive to find that functionality embedded in Orcad Capture, it doesn't exist. 

If so, do we have relevant TCL command to extract the signal information[s] under a netgroup to analyse netgroup modification?

Thanks in advance.