There is a Properties field listed under 'Misc' which allows (or disallows) "CCS per viewport", when I am working in a layout sheet. This is set to "Yes". But when I create a new CCS (Tools -> New CCS -> ...) it appears to apply it to the whole sheet, even if I locate the origin within a viewport. How do I apply a CCS to one viewport only?

(What I am trying to do is 'rotate' the viewport so that the view of the underlying model is at 90 deg to another viewport)

Thanks