Geometry - setting from script

[David Bovill]

If I have a group that resizes nicely using the geometry manager -  
say it fills the whole card - but now I want to shrink it to occupy a  
smaller size on the card (and the geometry manager to continue  
resizing the group proportionally).... how to do?

I have read about "revCacheGeometry" - which I think should do the  
job after shrinking the group - but how to shrink the group to a new  
rect in the same way that resizing the stack by hand would do?